DATA: id TYPE i.
...
id = request->get_form_field( 'invoiceID' ).
CONCATENATE `INVOICEID = '` id `'` INTO cl_where.
SELECT *
FROM invoices
INTO CORRESPONDING FIELDS OF TABLE itab_invoices
WHERE (cl_where).
ENDSELECT.
...
ID. Although the interface generates a list of invoice identifiers that belong to the current user, an attacker might bypass this interface to request any desired invoice. Because the code in this example does not check to ensure that the user has permission to access the requested invoice, it will display any invoice, even if it does not belong to the current user.
...
var params:Object = LoaderInfo(this.root.loaderInfo).parameters;
var id:int = int(Number(params["invoiceID"]));
var query:String = "SELECT * FROM invoices WHERE id = :id";
stmt.sqlConnection = conn;
stmt.text = query;
stmt.parameters[":id"] = id;
stmt.execute();
...
id. Although the interface generates a list of invoice identifiers that belong to the current user, an attacker might bypass this interface to request any desired invoice. Because the code in this example does not check to ensure that the user has permission to access the requested invoice, it will display any invoice, even if it does not belong to the current user.inputID value is originated from a pre-defined list, and a bind variable helps to prevent SOQL/SOSL injection.
...
result = [SELECT Name, Phone FROM Contact WHERE (IsDeleted = false AND Id=:inputID)];
...
inputID. If the attacker is able to bypass the interface and send a request with a different value he will have access to other contact information. Since the code in this example does not check to ensure that the user has permission to access the requested contact, it will display any contact, even if the user is not authorized to see it.
...
int16 id = System.Convert.ToInt16(invoiceID.Text);
var invoice = OrderSystem.getInvoices()
.Where(new Invoice { invoiceID = id });
...
id. Although the interface generates a list of invoice identifiers that belong to the current user, an attacker might bypass this interface to request any desired invoice. Because the code in this example does not check to ensure that the user has permission to access the requested invoice, it will display any invoice, even if it does not belong to the current user.
...
CMyRecordset rs(&dbms);
rs.PrepareSQL("SELECT * FROM invoices WHERE id = ?");
rs.SetParam_int(0,atoi(r.Lookup("invoiceID").c_str()));
rs.SafeExecuteSQL();
...
id. Although the interface generates a list of invoice identifiers that belong to the current user, an attacker might bypass this interface to request any desired invoice. Because the code in this example does not check to ensure that the user has permission to access the requested invoice, it will display any invoice, even if it does not belong to the current user.
...
ACCEPT ID.
EXEC SQL
DECLARE C1 CURSOR FOR
SELECT INVNO, INVDATE, INVTOTAL
FROM INVOICES
WHERE INVOICEID = :ID
END-EXEC.
...
ID. Although the interface generates a list of invoice identifiers that belong to the current user, an attacker might bypass this interface to request any desired invoice. Because the code in this example does not check to ensure that the user has permission to access the requested invoice, it will display any invoice, even if it does not belong to the current user.deleteDatabase method that contains a user-controlled database name can allow an attacker to delete any database.
...
id := request.FormValue("invoiceID")
query := "SELECT * FROM invoices WHERE id = ?";
rows, err := db.Query(query, id)
...
id. Although the interface generates a list of invoice identifiers that belong to the current user, an attacker might bypass this interface to request any desired invoice. Because the code in this example does not check to ensure that the user has permission to access the requested invoice, it will display any invoice, even if it does not belong to the current user.
...
id = Integer.decode(request.getParameter("invoiceID"));
String query = "SELECT * FROM invoices WHERE id = ?";
PreparedStatement stmt = conn.prepareStatement(query);
stmt.setInt(1, id);
ResultSet results = stmt.execute();
...
id. Although the interface generates a list of invoice identifiers that belong to the current user, an attacker might bypass this interface to request any desired invoice. Because the code in this example does not check to ensure that the user has permission to access the requested invoice, it will display any invoice, even if it does not belong to the current user.Example 1 to the Android platform.
...
String id = this.getIntent().getExtras().getString("invoiceID");
String query = "SELECT * FROM invoices WHERE id = ?";
SQLiteDatabase db = this.openOrCreateDatabase("DB", MODE_PRIVATE, null);
Cursor c = db.rawQuery(query, new Object[]{id});
...
...
var id = document.form.invoiceID.value;
var query = "SELECT * FROM invoices WHERE id = ?";
db.transaction(function (tx) {
tx.executeSql(query,[id]);
}
)
...
id. Although the interface generates a list of invoice identifiers that belong to the current user, an attacker might bypass this interface to request any desired invoice. Because the code in this example does not check to ensure that the user has permission to access the requested invoice, it will display any invoice, even if it does not belong to the current user.
...
NSManagedObjectContext *context = [appDelegate managedObjectContext];
NSEntityDescription *entityDesc = [NSEntityDescription entityForName:@"Invoices" inManagedObjectContext:context];
NSFetchRequest *request = [[NSFetchRequest alloc] init];
[request setEntity:entityDesc];
NSPredicate *pred = [NSPredicate predicateWithFormat:@"(id = %@)", invoiceId.text];
[request setPredicate:pred];
NSManagedObject *matches = nil;
NSError *error;
NSArray *objects = [context executeFetchRequest:request error:&error];
if ([objects count] == 0) {
status.text = @"No records found.";
} else {
matches = [objects objectAtIndex:0];
invoiceReferenceNumber.text = [matches valueForKey:@"invRefNum"];
orderNumber.text = [matches valueForKey:@"orderNumber"];
status.text = [NSString stringWithFormat:@"%d records found", [objects count]];
}
[request release];
...
id. Although the interface generates a list of invoice identifiers that belong to the current user, an attacker might bypass this interface to request any desired invoice. Because the code in this example does not check to ensure that the user has permission to access the requested invoice, it will display any invoice, even if it does not belong to the current user.
...
$id = $_POST['id'];
$query = "SELECT * FROM invoices WHERE id = ?";
$stmt = $mysqli->prepare($query);
$stmt->bind_param('ss',$id);
$stmt->execute();
...
id. Although the interface generates a list of invoice identifiers that belong to the current user, an attacker might bypass this interface to request any desired invoice. Because the code in this example does not check to ensure that the user has permission to access the requested invoice, it will display any invoice, even if it does not belong to the current user.
procedure get_item (
itm_cv IN OUT ItmCurTyp,
id in varchar2)
is
open itm_cv for ' SELECT * FROM items WHERE ' ||
'invoiceID = :invid' ||
using id;
end get_item;
id. Although the interface generates a list of invoice identifiers that belong to the current user, an attacker might bypass this interface to request any desired invoice. Because the code in this example does not check to ensure that the user has permission to access the requested invoice, it will display any invoice, even if it does not belong to the current user.
...
id = request.POST['id']
c = db.cursor()
stmt = c.execute("SELECT * FROM invoices WHERE id = %s", (id,))
...
id. Although the interface generates a list of invoice identifiers that belong to the current user, an attacker might bypass this interface to request any desired invoice. Because the code in this example does not check to ensure that the user has permission to access the requested invoice, it will display any invoice, even if it does not belong to the current user.
...
id = req['invoiceID'].respond_to(:to_int)
query = "SELECT * FROM invoices WHERE id=?"
stmt = conn.prepare(query)
stmt.execute(id)
...
id. Although the interface generates a list of invoice identifiers that belong to the current user, an attacker might bypass this interface to request any desired invoice. Because the code in this example does not check to ensure that the user has permission to access the requested invoice, it will display any invoice, even if it does not belong to the current user.
def searchInvoice(value:String) = Action.async { implicit request =>
val result: Future[Seq[Invoice]] = db.run {
sql"select * from invoices where id=$value".as[Invoice]
}
...
}
id. Although the interface generates a list of invoice identifiers that belong to the current user, an attacker might bypass this interface to request any desired invoice. Because the code in this example does not check to ensure that the user has permission to access the requested invoice, it will display any invoice, even if it does not belong to the current user.
...
let fetchRequest = NSFetchRequest()
let entity = NSEntityDescription.entityForName("Invoices", inManagedObjectContext: managedContext)
fetchRequest.entity = entity
let pred : NSPredicate = NSPredicate(format:"(id = %@)", invoiceId.text)
fetchRequest.setPredicate = pred
do {
let results = try managedContext.executeFetchRequest(fetchRequest)
let result : NSManagedObject = results.first!
invoiceReferenceNumber.text = result.valueForKey("invRefNum")
orderNumber.text = result.valueForKey("orderNumber")
status.text = "\(results.count) records found"
} catch let error as NSError {
print("Error \(error)")
}
...
id. Although the interface generates a list of invoice identifiers that belong to the current user, an attacker might bypass this interface to request any desired invoice. Because the code in this example does not check to ensure that the user has permission to access the requested invoice, it will display any invoice, even if it does not belong to the current user.
...
id = Request.Form("invoiceID")
strSQL = "SELECT * FROM invoices WHERE id = ?"
objADOCommand.CommandText = strSQL
objADOCommand.CommandType = adCmdText
set objADOParameter = objADOCommand.CreateParameter("id" , adString, adParamInput, 0, 0)
objADOCommand.Parameters("id") = id
...
id. Although the interface generates a list of invoice identifiers that belong to the current user, an attacker might bypass this interface to request any desired invoice. Because the code in this example does not check to ensure that the user has permission to access the requested invoice, it will display any invoice, even if it does not belong to the current user.APPHOME to determine the directory in which it is installed and then executes an initialization script based on a relative path from the specified directory.
...
CALL FUNCTION 'REGISTRY_GET'
EXPORTING
KEY = 'APPHOME'
IMPORTING
VALUE = home.
CONCATENATE home INITCMD INTO cmd.
CALL 'SYSTEM' ID 'COMMAND' FIELD cmd ID 'TAB' FIELD TABL[].
...
Example 1 allows an attacker to execute arbitrary commands with the elevated privilege of the application by modifying the registry entry APPHOME to point to a different path containing a malicious version of INITCMD. Because the program does not validate the value read from the registry, if an attacker can control the value of the registry key APPHOME, then they can fool the application into running malicious code and take control of the system.rman utility and then run a cleanup.bat script to delete some temporary files. The script rmanDB.bat accepts a single command line parameter, which specifies the type of backup to perform. Because access to the database is restricted, the application runs the backup as a privileged user.
...
btype = request->get_form_field( 'backuptype' )
CONCATENATE `/K 'c:\\util\\rmanDB.bat ` btype `&&c:\\util\\cleanup.bat'` INTO cmd.
CALL FUNCTION 'SXPG_COMMAND_EXECUTE_LONG'
EXPORTING
commandname = cmd_exe
long_params = cmd_string
EXCEPTIONS
no_permission = 1
command_not_found = 2
parameters_too_long = 3
security_risk = 4
OTHERS = 5.
...
backuptype parameter read from the user. Typically the function module SXPG_COMMAND_EXECUTE_LONG will not execute multiple commands, but in this case the program first runs the cmd.exe shell in order to run multiple commands with a single call to CALL 'SYSTEM'. After the shell is invoked, it will allow for the execution of multiple commands separated by two ampersands. If an attacker passes a string of the form "&& del c:\\dbms\\*.*", then the application will execute this command along with the others specified by the program. Because of the nature of the application, it runs with the privileges necessary to interact with the database, which means whatever command the attacker injects will run with those privileges as well.make command in the /var/yp directory.
...
MOVE 'make' to cmd.
CALL 'SYSTEM' ID 'COMMAND' FIELD cmd ID 'TAB' FIELD TABL[].
...
CALL 'SYSTEM'. If an attacker can modify the $PATH variable to point to a malicious binary called make and cause the program to be executed in their environment, then the malicious binary will be loaded instead of the one intended. Because of the nature of the application, it runs with the privileges necessary to perform system operations, which means the attacker's make will now be run with these privileges, possibly giving the attacker complete control of the system.
...
var fs:FileStream = new FileStream();
fs.open(new File(String(configStream.readObject())+".txt"), FileMode.READ);
home = String(fs.readObject(home));
var cmd:String = home + INITCMD;
fscommand("exec", cmd);
...
Example 1 allows an attacker to execute arbitrary commands with the elevated privilege of the application by modifying the contents of the configuration file configStream to point to a different path containing a malicious version of INITCMD. Because the program does not validate the value read from the file, if an attacker can control that value, then they can fool the application into running malicious code and take control of the system.rman utility and then run a cleanup.bat script to delete some temporary files. The script rmanDB.bat accepts a single command line parameter, which specifies the type of backup to perform. Because access to the database is restricted, the application runs the backup as a privileged user.
...
var params:Object = LoaderInfo(this.root.loaderInfo).parameters;
var btype:String = String(params["backuptype"]);
var cmd:String = "cmd.exe /K \"c:\\util\\rmanDB.bat " + btype + "&&c:\\util\\cleanup.bat\"";
fscommand("exec", cmd);
...
backuptype parameter read from the user. Typically the fscommand() function will not execute multiple commands, but in this case the program first runs the cmd.exe shell in order to run multiple commands with a single call to fscommnd(). After the shell is invoked, it will allow for the execution of multiple commands separated by two ampersands. If an attacker passes a string of the form "&& del c:\\dbms\\*.*", then the application will execute this command along with the others specified by the program. Because of the nature of the application, it runs with the privileges necessary to interact with the database, which means whatever command the attacker injects will run with those privileges as well.make command in the /var/yp directory.
...
fscommand("exec", "make");
...
fscommand(). If an attacker can modify the $PATH variable to point to a malicious binary called make and cause the program to be executed in their environment, then the malicious binary will be loaded instead of the one intended. Because of the nature of the application, it runs with the privileges necessary to perform system operations, which means the attacker's make will now be run with these privileges, possibly giving the attacker complete control of the system.APPHOME to determine the directory in which it is installed and then executes an initialization script based on a relative path from the specified directory.
...
string val = Environment.GetEnvironmentVariable("APPHOME");
string cmd = val + INITCMD;
ProcessStartInfo startInfo = new ProcessStartInfo(cmd);
Process.Start(startInfo);
...
Example 1 allows an attacker to execute arbitrary commands with the elevated privilege of the application by modifying the system property APPHOME to point to a different path containing a malicious version of INITCMD. Because the program does not validate the value read from the environment, if an attacker can control the value of the system property APPHOME, then they can fool the application into running malicious code and take control of the system.rman utility and then run a cleanup.bat script to delete some temporary files. The script rmanDB.bat accepts a single command line parameter, which specifies the type of backup to perform. Because access to the database is restricted, the application runs the backup as a privileged user.
...
string btype = BackupTypeField.Text;
string cmd = "cmd.exe /K \"c:\\util\\rmanDB.bat"
+ btype + "&&c:\\util\\cleanup.bat\""));
Process.Start(cmd);
...
BackupTypeField. Typically the Process.Start() function will not execute multiple commands, but in this case the program first runs the cmd.exe shell in order to run multiple commands with a single call to Process.Start(). After the shell is invoked, it will allow for the execution of multiple commands separated by two ampersands. If an attacker passes a string of the form "&& del c:\\dbms\\*.*", then the application will execute this command along with the others specified by the program. Because of the nature of the application, it runs with the privileges necessary to interact with the database, which means whatever command the attacker injects will run with those privileges as well.update.exe command, as follows:
...
Process.Start("update.exe");
...
Process.start(). If an attacker can modify the $PATH variable to point to a malicious binary called update.exe and cause the program to be executed in their environment, then the malicious binary will be loaded instead of the one intended. Because of the nature of the application, it runs with the privileges necessary to perform system operations, which means the attacker's update.exe will now be run with these privileges, possibly giving the attacker complete control of the system.setuid root because it is intended for use as a learning tool to allow system administrators in-training to inspect privileged system files without giving them the ability to modify them or damage the system.
int main(char* argc, char** argv) {
char cmd[CMD_MAX] = "/usr/bin/cat ";
strcat(cmd, argv[1]);
system(cmd);
}
root privileges, the call to system() also executes with root privileges. If a user specifies a standard filename, the call works as expected. However, if an attacker passes a string of the form ";rm -rf /", then the call to system() fails to execute cat due to a lack of arguments and then plows on to recursively delete the contents of the root partition.$APPHOME to determine the application's installation directory and then executes an initialization script in that directory.
...
char* home=getenv("APPHOME");
char* cmd=(char*)malloc(strlen(home)+strlen(INITCMD));
if (cmd) {
strcpy(cmd,home);
strcat(cmd,INITCMD);
execl(cmd, NULL);
}
...
Example 1, the code in this example allows an attacker to execute arbitrary commands with the elevated privilege of the application. In this example, the attacker may modify the environment variable $APPHOME to specify a different path containing a malicious version of INITCMD. Because the program does not validate the value read from the environment, by controlling the environment variable the attacker may fool the application into running malicious code.make in the /var/yp directory. Note that since the program updates password records, it has been installed setuid root.make as follows:
system("cd /var/yp && make &> /dev/null");
system(). However, since the program does not specify an absolute path for make and does not scrub any environment variables prior to invoking the command, the attacker may modify their $PATH variable to point to a malicious binary named make and execute the CGI script from a shell prompt. And since the program has been installed setuid root, the attacker's version of make now runs with root privileges.CreateProcess() either directly or via a call to one of the functions in the _spawn() family, care must be taken when there is a space in an executable or path.
...
LPTSTR cmdLine = _tcsdup(TEXT("C:\\Program Files\\MyApplication -L -S"));
CreateProcess(NULL, cmdLine, ...);
...
CreateProcess() parses spaces, the first executable the operating system will try to execute is Program.exe, not MyApplication.exe. Therefore, if an attacker is able to install a malicious application called Program.exe on the system, any program that incorrectly calls CreateProcess() using the Program Files directory will run this application instead of the intended one.system(), exec(), and CreateProcess() use the environment of the program that calls them, and therefore attackers have a potential opportunity to influence the behavior of these calls.$PATH or other aspects of the program's execution environment.make in the /var/yp directory. Note that because the program updates password records, it has been installed setuid root.make as follows:
MOVE "cd /var/yp && make &> /dev/null" to command-line
CALL "CBL_EXEC_RUN_UNIT" USING command-line
length of command-line
run-unit-id
stack-size
flags
CBL_EXEC_RUN_UNIT. However, because the program does not specify an absolute path for make and does not scrub its environment variables prior to invoking the command, the attacker can modify their $PATH variable to point to a malicious binary named make and execute the CGI script from a shell prompt. In addition, because the program has been installed setuid root, the attacker's version of make now runs with root privileges.pdfprint command.
DISPLAY "TEMP" UPON ENVIRONMENT-NAME
ACCEPT ws-temp-dir FROM ENVIRONMENT-VARIABLE
STRING "pdfprint " DELIMITED SIZE
ws-temp-dir DELIMITED SPACE
"/" DELIMITED SIZE
ws-pdf-filename DELIMITED SPACE
x"00" DELIMITED SIZE
INTO cmd-buffer
CALL "SYSTEM" USING cmd-buffer
pdfprint, the attacker can modify their $PATH variable to point to a malicious binary. Furthermore, while the DELIMITED SPACE phrases prevent embedded spaces in ws-temp-dir and ws-pdf-filename, there could be shell metacharacters (such as &&) embedded in either.cmd request parameter.
...
<cfset var="#url.cmd#">
<cfexecute name = "C:\windows\System32\cmd.exe"
arguments = "/c #var#"
timeout = "1"
variable="mycmd">
</cfexecute>
...
APPHOME to determine the directory in which it is installed and then executes an initialization script based on a relative path from the specified directory.
...
final cmd = String.fromEnvironment('APPHOME');
await Process.run(cmd);
...
Example 1 allows an attacker to execute arbitrary commands with the elevated privilege of the application by modifying the system property APPHOME to point to a different path containing a malicious version of INITCMD. Because the program does not validate the value read from the environment, if an attacker can control the value of the system property APPHOME, then they can fool the application into running malicious code and take control of the system.
cmdName := request.FormValue("Command")
c := exec.Command(cmdName)
c.Run()
APPHOME to determine the directory in which it is installed and then executes an initialization script based on a relative path from the specified directory.
...
String home = System.getProperty("APPHOME");
String cmd = home + INITCMD;
java.lang.Runtime.getRuntime().exec(cmd);
...
Example 1 allows an attacker to execute arbitrary commands with the elevated privilege of the application by modifying the system property APPHOME to point to a different path containing a malicious version of INITCMD. Because the program does not validate the value read from the environment, if an attacker can control the value of the system property APPHOME, then they can fool the application into running malicious code and take control of the system.rman utility and then run a cleanup.bat script to delete some temporary files. The script rmanDB.bat accepts a single command line parameter, which specifies the type of backup to perform. Because access to the database is restricted, the application runs the backup as a privileged user.
...
String btype = request.getParameter("backuptype");
String cmd = new String("cmd.exe /K
\"c:\\util\\rmanDB.bat "+btype+"&&c:\\util\\cleanup.bat\"")
System.Runtime.getRuntime().exec(cmd);
...
backuptype parameter read from the user. Typically the Runtime.exec() function will not execute multiple commands, but in this case the program first runs the cmd.exe shell in order to run multiple commands with a single call to Runtime.exec(). After the shell is invoked, it will allow for the execution of multiple commands separated by two ampersands. If an attacker passes a string of the form "&& del c:\\dbms\\*.*", then the application will execute this command along with the others specified by the program. Because of the nature of the application, it runs with the privileges necessary to interact with the database, which means whatever command the attacker injects will run with those privileges as well.make command in the /var/yp directory.
...
System.Runtime.getRuntime().exec("make");
...
Runtime.exec(). If an attacker can modify the $PATH variable to point to a malicious binary called make and cause the program to be executed in their environment, then the malicious binary will be loaded instead of the one intended. Because of the nature of the application, it runs with the privileges necessary to perform system operations, which means the attacker's make will now be run with these privileges, possibly giving the attacker complete control of the system.
...
String[] cmds = this.getIntent().getStringArrayExtra("commands");
Process p = Runtime.getRuntime().exec("su");
DataOutputStream os = new DataOutputStream(p.getOutputStream());
for (String cmd : cmds) {
os.writeBytes(cmd+"\n");
}
os.writeBytes("exit\n");
os.flush();
...
APPHOME to determine the directory in which it is installed and then executes an initialization script based on a relative path from the specified directory.
var cp = require('child_process');
...
var home = process.env('APPHOME');
var cmd = home + INITCMD;
child = cp.exec(cmd, function(error, stdout, stderr){
...
});
...
Example 1 allows an attacker to execute arbitrary commands with the elevated privilege of the application by modifying the system property APPHOME to point to a different path containing a malicious version of INITCMD. Since the program does not validate the value read from the environment, if an attacker can control the value of the system property APPHOME, then they can fool the application into running malicious code and take control of the system.rman utility. The script rmanDB.bat accepts a single command line parameter, which specifies the type of backup to perform. Because access to the database is restricted, the application runs the backup as a privileged user.
var cp = require('child_process');
var http = require('http');
var url = require('url');
function listener(request, response){
var btype = url.parse(request.url, true)['query']['backuptype'];
if (btype !== undefined){
cmd = "c:\\util\\rmanDB.bat" + btype;
cp.exec(cmd, function(error, stdout, stderr){
...
});
}
...
}
...
http.createServer(listener).listen(8080);
backuptype parameter read from the user apart from verifying its existence. After the shell is invoked, it may allow for the execution of multiple commands, and due to the nature of the application, it will run with the privileges necessary to interact with the database, which means whatever command the attacker injects will run with those privileges as well.make command in the /var/yp directory.
...
require('child_process').exec("make", function(error, stdout, stderr){
...
});
...
make and fails to clean its environment prior to executing the call to child_process.exec(). If an attacker can modify the $PATH variable to point to a malicious binary called make and cause the program to be executed in their environment, then the malicious binary will be loaded instead of the one intended. Because of the nature of the application, it runs with the privileges necessary to perform system operations, which means the attacker's make will now be run with these privileges, possibly giving the attacker complete control of the system.APPHOME to determine the directory in which it is installed and then executes an initialization script based on a relative path from the specified directory.
...
$home = $_ENV['APPHOME'];
$cmd = $home . $INITCMD;
system(cmd);
...
Example 1 allows an attacker to execute arbitrary commands with the elevated privilege of the application by modifying the system property APPHOME to point to a different path containing a malicious version of INITCMD. Because the program does not validate the value read from the environment, if an attacker can control the value of the system property APPHOME, then they can fool the application into running malicious code and take control of the system.rman utility and then run a cleanup.bat script to delete some temporary files. The script rmanDB.bat accepts a single command line parameter, which specifies the type of backup to perform. Because access to the database is restricted, the application runs the backup as a privileged user.
...
$btype = $_GET['backuptype'];
$cmd = "cmd.exe /K \"c:\\util\\rmanDB.bat " . $btype . "&&c:\\util\\cleanup.bat\"";
system(cmd);
...
backuptype parameter read from the user. Typically the Runtime.exec() function will not execute multiple commands, but in this case the program first runs the cmd.exe shell in order to run multiple commands with a single call to Runtime.exec(). After the shell is invoked, it will allow for the execution of multiple commands separated by two ampersands. If an attacker passes a string of the form "&& del c:\\dbms\\*.*", then the application will execute this command along with the others specified by the program. Because of the nature of the application, it runs with the privileges necessary to interact with the database, which means whatever command the attacker injects will run with those privileges as well.make command in the /var/yp directory.
...
$result = shell_exec("make");
...
Runtime.exec(). If an attacker can modify the $PATH variable to point to a malicious binary called make and cause the program to be executed in their environment, then the malicious binary will be loaded instead of the one intended. Because of the nature of the application, it runs with the privileges necessary to perform system operations, which means the attacker's make will now be run with these privileges, possibly giving the attacker complete control of the system.
...
CREATE PROCEDURE dbo.listFiles (@path NVARCHAR(200))
AS
DECLARE @cmd NVARCHAR(500)
SET @cmd = 'dir ' + @path
exec xp_cmdshell @cmd
GO
...
APPHOME to determine the directory in which it is installed and then executes an initialization script based on a relative path from the specified directory.
...
home = os.getenv('APPHOME')
cmd = home.join(INITCMD)
os.system(cmd);
...
Example 1 allows an attacker to execute arbitrary commands with the elevated privilege of the application by modifying the system property APPHOME to point to a different path containing a malicious version of INITCMD. Because the program does not validate the value read from the environment, if an attacker can control the value of the system property APPHOME, then they can fool the application into running malicious code and take control of the system.rman utility and then run a cleanup.bat script to delete some temporary files. The script rmanDB.bat accepts a single command line parameter, which specifies the type of backup to perform. Because access to the database is restricted, the application runs the backup as a privileged user.
...
btype = req.field('backuptype')
cmd = "cmd.exe /K \"c:\\util\\rmanDB.bat " + btype + "&&c:\\util\\cleanup.bat\""
os.system(cmd);
...
backuptype parameter read from the user. Typically the Runtime.exec() function will not execute multiple commands, but in this case the program first runs the cmd.exe shell in order to run multiple commands with a single call to Runtime.exec(). After the shell is invoked, it will allow for the execution of multiple commands separated by two ampersands. If an attacker passes a string of the form "&& del c:\\dbms\\*.*", then the application will execute this command along with the others specified by the program. Because of the nature of the application, it runs with the privileges necessary to interact with the database, which means whatever command the attacker injects will run with those privileges as well.make command in the /var/yp directory.
...
result = os.system("make");
...
os.system(). If an attacker can modify the $PATH variable to point to a malicious binary called make and cause the program to be executed in their environment, then the malicious binary will be loaded instead of the one intended. Because of the nature of the application, it runs with the privileges necessary to perform system operations, which means the attacker's make will now be run with these privileges, possibly giving the attacker complete control of the system.APPHOME to determine the directory in which it is installed and then executes an initialization script based on a relative path from the specified directory.
...
home = ENV['APPHOME']
cmd = home + INITCMD
Process.spawn(cmd)
...
Example 1 allows an attacker to execute arbitrary commands with the elevated privilege of the application by modifying the system property APPHOME to point to a different path containing a malicious version of INITCMD. Because the program does not validate the value read from the environment, if an attacker can control the value of the system property APPHOME, then they can fool the application into running malicious code and take control of the system.rman utility and then run a cleanup.bat script to delete some temporary files. The script rmanDB.bat accepts a single command line parameter, which specifies the type of backup to perform. Because access to the database is restricted, the application runs the backup as a privileged user.
...
btype = req['backuptype']
cmd = "C:\\util\\rmanDB.bat #{btype} &&C:\\util\\cleanup.bat"
spawn(cmd)
...
backuptype parameter read from the user. After the shell is invoked via Kernel.spawn, it will allow for the execution of multiple commands separated by two ampersands. If an attacker passes a string of the form "&& del c:\\dbms\\*.*", then the application will execute this command along with the others specified by the program. Because of the nature of the application, it runs with the privileges necessary to interact with the database, which means whatever command the attacker injects will run with those privileges as well.make command in the /var/yp directory.
...
system("make")
...
Kernel.system(). If an attacker can modify the $PATH variable to point to a malicious binary called make and cause the program to be executed in their environment, then the malicious binary will be loaded instead of the one intended. Because of the nature of the application, it runs with the privileges necessary to perform system operations, which means the attacker's make will now be run with these privileges, possibly giving the attacker complete control of the system.
def changePassword(username: String, password: String) = Action { request =>
...
s'echo "${password}" | passwd ${username} --stdin'.!
...
}
APPHOME to determine the directory in which it is installed and then executes an initialization script based on a relative path from the specified directory.
...
Dim cmd
Dim home
home = Environ$("AppHome")
cmd = home & initCmd
Shell cmd, vbNormalFocus
...
Example 1 allows an attacker to execute arbitrary commands with the elevated privilege of the application by modifying the system property APPHOME to point to a different path containing a malicious version of INITCMD. Because the program does not validate the value read from the environment, if an attacker can control the value of the system property APPHOME, then they can fool the application into running malicious code and take control of the system.rman utility and then run a cleanup.bat script to delete some temporary files. The script rmanDB.bat accepts a single command line parameter, which specifies the type of backup to perform. Because access to the database is restricted, the application runs the backup as a privileged user.
...
btype = Request.Form("backuptype")
cmd = "cmd.exe /K " & Chr(34) & "c:\util\rmanDB.bat " & btype & "&&c:\util\cleanup.bat" & Chr(34) & ";
Shell cmd, vbNormalFocus
...
backuptype parameter read from the user. After the shell is invoked, it will allow for the execution of multiple commands separated by two ampersands. If an attacker passes a string of the form "&& del c:\\dbms\\*.*", then the application will execute this command along with the others specified by the program. Because of the nature of the application, it runs with the privileges necessary to interact with the database, which means whatever command the attacker injects will run with those privileges as well.make command in the /var/yp directory.
...
$result = shell_exec("make");
...
Runtime.exec(). If an attacker can modify the $PATH variable to point to a malicious binary called make and cause the program to be executed in their environment, then the malicious binary will be loaded instead of the one intended. Because of the nature of the application, it runs with the privileges necessary to perform system operations, which means the attacker's make will now be run with these privileges, possibly giving the attacker complete control of the system.isSecure parameter set to true.Secure flag for each cookie. If the flag is set, the browser will only send the cookie over HTTPS. Sending cookies over an unencrypted channel can expose them to network sniffing attacks, and the secure flag helps keep a cookie's value confidential. This is especially important if the cookie contains private data or carries a session identifier.isSecure parameter to true.
...
Cookie cookie = new Cookie('emailCookie', emailCookie, path, maxAge, false, 'Strict');
...
isSecure parameter, cookies sent during an HTTPS request are also sent during subsequent HTTP requests. Sniffing network traffic over unencrypted wireless connections is a trivial task for attackers, and sending cookies (especially those with session IDs) over HTTP can result in application compromise.Secure flag set to true.Secure flag for each cookie. If the flag is set, the browser will only send the cookie over HTTPS. Sending cookies over an unencrypted channel can expose them to network sniffing attacks, so the secure flag helps keep a cookie's value confidential. This is especially important if the cookie contains private data or carries a session identifier.Secure property.
...
HttpCookie cookie = new HttpCookie("emailCookie", email);
Response.AppendCookie(cookie);
...
Secure flag, cookies sent during an HTTPS request will also be sent during subsequent HTTP requests. Sniffing network traffic over unencrypted wireless connections is a trivial task for attackers, so sending cookies (especially those with session IDs) over HTTP can result in application compromise.Secure flag to trueSecure flag for each cookie. If the flag is set, the browser will only send the cookie over HTTPS. Sending cookies over an unencrypted channel can expose them to network sniffing attacks, so the secure flag helps keep a cookie's value confidential. This is especially important if the cookie contains private data or session identifiers, or carries a CSRF token.Secure flag.
cookie := http.Cookie{
Name: "emailCookie",
Value: email,
}
http.SetCookie(response, &cookie)
...
Secure flag, cookies sent during an HTTPS request will also be sent during subsequent HTTP requests. Attackers can then compromise the cookie by sniffing the unencrypted network traffic, which is particularly easy over wireless networks.Secure flag set to true.Secure flag for each cookie. If the flag is set, the browser will only send the cookie over HTTPS. Sending cookies over an unencrypted channel can expose them to network sniffing attacks, so the secure flag helps keep a cookie's value confidential. This is especially important if the cookie contains private data or carries a session identifier.use-secure-cookie attribute enables the remember-me cookie to be sent over unencrypted transport.
<http auto-config="true">
...
<remember-me use-secure-cookie="false"/>
</http>
Secure flag, cookies sent during an HTTPS request will also be sent during subsequent HTTP requests. Sniffing network traffic over unencrypted wireless connections is a trivial task for attackers, so sending cookies (especially those with session IDs) over HTTP can result in application compromise.Secure flag set to true.Secure flag for each cookie. If the flag is set, the browser will only send the cookie over HTTPS. Sending cookies over an unencrypted channel can expose them to network sniffing attacks, so the secure flag helps keep a cookie's value confidential. This is especially important if the cookie contains private data or carries a session identifier.Secure property to true.
res.cookie('important_cookie', info, {domain: 'secure.example.com', path: '/admin', httpOnly: true, secure: false});
Secure flag, cookies sent during an HTTPS request will also be sent during subsequent HTTP requests. Sniffing network traffic over unencrypted wireless connections is a trivial task for attackers, so sending cookies (especially those with session IDs) over HTTP can result in application compromise.NSHTTPCookieSecure flag set to TRUE.Secure flag for each cookie. If the flag is set, the browser will only send the cookie over HTTPS. Sending cookies over an unencrypted channel can expose them to network sniffing attacks, so the secure flag helps keep a cookie's value confidential. This is especially important if the cookie contains private data or carries a session identifier.Secure flag.
...
NSDictionary *cookieProperties = [NSDictionary dictionary];
...
NSHTTPCookie *cookie = [NSHTTPCookie cookieWithProperties:cookieProperties];
...
Secure flag, cookies sent during an HTTPS request will also be sent during subsequent HTTP requests. Sniffing network traffic over unencrypted wireless connections is a trivial task for attackers, so sending cookies (especially those with session IDs) over HTTP can result in application compromise.Secure flag to trueSecure flag for each cookie. If the flag is set, the browser will only send the cookie over HTTPS. Sending cookies over an unencrypted channel can expose them to network sniffing attacks, so the secure flag helps keep a cookie's value confidential. This is especially important if the cookie contains private data or carries a session identifier.Secure flag.
...
setcookie("emailCookie", $email, 0, "/", "www.example.com");
...
Secure flag, cookies sent during an HTTPS request will also be sent during subsequent HTTP requests. Attackers can then compromise the cookie by sniffing the unencrypted network traffic, which is particularly easy over wireless networks.Secure flag to TrueSecure flag for each cookie. If the flag is set, the browser will only send the cookie over HTTPS. Sending cookies over an unencrypted channel can expose them to network sniffing attacks, so the secure flag helps keep a cookie's value confidential. This is especially important if the cookie contains private data or session identifiers, or carries a CSRF token.Secure flag.
from django.http.response import HttpResponse
...
def view_method(request):
res = HttpResponse()
res.set_cookie("emailCookie", email)
return res
...
Secure flag, cookies sent during an HTTPS request will also be sent during subsequent HTTP requests. Attackers can then compromise the cookie by sniffing the unencrypted network traffic, which is particularly easy over wireless networks.Secure flag set to true.Secure flag for each cookie. If the flag is set, the browser will only send the cookie over HTTPS. Sending cookies over an unencrypted channel can expose them to network sniffing attacks, so the secure flag helps keep a cookie's value confidential. This is especially important if the cookie contains private data or carries a session identifier.Secure flag.
Ok(Html(command)).withCookies(Cookie("sessionID", sessionID, secure = false))
Secure flag, cookies sent during an HTTPS request will also be sent during subsequent HTTP requests. Sniffing network traffic over unencrypted wireless connections is a trivial task for attackers, so sending cookies (especially those with session IDs) over HTTP can result in application compromise.NSHTTPCookieSecure flag set to TRUE.Secure flag for each cookie. If the flag is set, the browser will only send the cookie over HTTPS. Sending cookies over an unencrypted channel can expose them to network sniffing attacks, so the secure flag helps keep a cookie's value confidential. This is especially important if the cookie contains private data or carries a session identifier.Secure flag.
...
let properties = [
NSHTTPCookieDomain: "www.example.com",
NSHTTPCookiePath: "/service",
NSHTTPCookieName: "foo",
NSHTTPCookieValue: "bar"
]
let cookie : NSHTTPCookie? = NSHTTPCookie(properties:properties)
...
Secure flag, cookies sent during an HTTPS request will also be sent during subsequent HTTP requests. Sniffing network traffic over unencrypted wireless connections is a trivial task for attackers, so sending cookies (especially those with session IDs) over HTTP can result in application compromise.HttpOnly flag to true.HttpOnly cookie property to prevent client-side scripts from accessing the cookie. Cross-site scripting attacks often access cookies in an attempt to steal session identifiers or authentication tokens. Without the HttpOnly flag enabled, attackers have easier access to user cookies.HttpOnly property.
HttpCookie cookie = new HttpCookie("emailCookie", email);
Response.AppendCookie(cookie);
HttpOnly flag to true.HttpOnly cookie property that prevents client-side scripts from accessing the cookie. Cross-site scripting attacks often access cookies in an attempt to steal session identifiers or authentication tokens. Without HttpOnly enabled, attackers have easier access to user cookies.HttpOnly property.
cookie := http.Cookie{
Name: "emailCookie",
Value: email,
}
...
HttpOnly flag to true.HttpOnly cookie property to prevent client-side scripts from accessing the cookie. Cross-site scripting attacks often access cookies in an attempt to steal session identifiers or authentication tokens. Without the HttpOnly flag enabled, attackers have easier access to user cookies.HttpOnly property.
javax.servlet.http.Cookie cookie = new javax.servlet.http.Cookie("emailCookie", email);
// Missing a call to: cookie.setHttpOnly(true);
HttpOnly flag to true.HttpOnly cookie property to prevent client-side scripts from accessing the cookie. Cross-site scripting attacks often access cookies in an attempt to steal session identifiers or authentication tokens. Without the HttpOnly flag enabled, attackers have easier access to user cookies.httpOnly property.
res.cookie('important_cookie', info, {domain: 'secure.example.com', path: '/admin'});
HttpOnly flag to true.HttpOnly cookie property to prevent client-side scripts from accessing the cookie. Cross-site scripting attacks often access cookies in an attempt to steal session identifiers or authentication tokens. Without the HttpOnly flag enabled, attackers have easier access to user cookies.HttpOnly property.
setcookie("emailCookie", $email, 0, "/", "www.example.com", TRUE); //Missing 7th parameter to set HttpOnly
HttpOnly flag to True.HttpOnly cookie property that prevents client-side scripts from accessing the cookie. Cross-site scripting attacks often access cookies in an attempt to steal session identifiers or authentication tokens. Without HttpOnly enabled, attackers have easier access to user cookies.HttpOnly property.
from django.http.response import HttpResponse
...
def view_method(request):
res = HttpResponse()
res.set_cookie("emailCookie", email)
return res
...
HttpOnly flag to true.HttpOnly cookie property to prevent client-side scripts from accessing the cookie. Cross-site scripting attacks often access cookies in an attempt to steal session identifiers or authentication tokens. Without the HttpOnly flag enabled, attackers have easier access to user cookies.HttpOnly property.
Ok(Html(command)).withCookies(Cookie("sessionID", sessionID, httpOnly = false))
.example.com". This exposes the cookie to all web applications on the base domain and any sub-domains. Because cookies often carry sensitive information such as session identifiers, sharing cookies across applications can cause a vulnerability in one application to compromise another application.http://secure.example.com/, and the application sets a session ID cookie with the domain ".example.com" when a user logs in.
HttpCookie cookie = new HttpCookie("sessionID", sessionID);
cookie.Domain = ".example.com";
http://insecure.example.com/ and it contains a cross-site scripting vulnerability. Any user authenticated to http://secure.example.com that browses to http://insecure.example.com risks exposing their session cookie from http://secure.example.com.insecure.example.com to create its own overly broad cookie that overwrites the cookie from secure.example.com..example.com". This exposes the cookie to all web applications on the base domain and any sub-domains. Because cookies often carry sensitive information such as session identifiers, sharing cookies across applications can cause a vulnerability in one application to compromise another application.http://secure.example.com/ and the application sets a session ID cookie with the domain ".example.com" when a user logs in.
cookie := http.Cookie{
Name: "sessionID",
Value: getSessionID(),
Domain: ".example.com",
}
...
http://insecure.example.com/, and it contains a cross-site scripting vulnerability. Any user authenticated to http://secure.example.com that browses to http://insecure.example.com risks exposing their session cookie from http://secure.example.com.insecure.example.com to create its own overly broad cookie that overwrites the cookie from Secure.example.com..example.com". This exposes the cookie to all web applications on the base domain and any sub-domains. Because cookies often carry sensitive information such as session identifiers, sharing cookies across applications can cause a vulnerability in one application to compromise another application.http://secure.example.com/ and the application sets a session ID cookie with the domain ".example.com" when a user logs in.
Cookie cookie = new Cookie("sessionID", sessionID);
cookie.setDomain(".example.com");
http://insecure.example.com/, and it contains a cross-site scripting vulnerability. Any user authenticated to http://secure.example.com that browses to http://insecure.example.com risks exposing their session cookie from http://secure.example.com.insecure.example.com to create its own overly broad cookie that overwrites the cookie from secure.example.com..example.com". This exposes the cookie to all web applications on the base domain and any sub-domains. Because cookies often carry sensitive information such as session identifiers, sharing cookies across applications can cause a vulnerability in one application to compromise another application.http://secure.example.com/ and the application sets a session ID cookie with the domain ".example.com" when a user logs in.
cookie_options = {};
cookie_options.domain = '.example.com';
...
res.cookie('important_cookie', info, cookie_options);
http://insecure.example.com/, and it contains a cross-site scripting vulnerability. Any user authenticated to http://secure.example.com that browses to http://insecure.example.com risks exposing their session cookie from http://secure.example.com.insecure.example.com to create its own overly broad cookie that overwrites the cookie from secure.example.com..example.com". This exposes the cookie to all web applications on the base domain and any sub-domains. Because cookies often carry sensitive information such as session identifiers, sharing cookies across applications can cause a vulnerability in one application to compromise another application.http://secure.example.com/ and the application sets a session ID cookie with the domain ".example.com" when a user logs in.
...
NSDictionary *cookieProperties = [NSDictionary dictionary];
...
[cookieProperties setValue:@".example.com" forKey:NSHTTPCookieDomain];
...
NSHTTPCookie *cookie = [NSHTTPCookie cookieWithProperties:cookieProperties];
...
http://insecure.example.com/, and it contains a cross-site scripting vulnerability. Any user authenticated to http://secure.example.com that browses to http://insecure.example.com risks exposing their session cookie from http://secure.example.com.insecure.example.com to create its own overly broad cookie that overwrites the cookie from secure.example.com..example.com". This exposes the cookie to all web applications on the base domain and any sub-domains. Because cookies often carry sensitive information such as session identifiers, sharing cookies across applications can cause a vulnerability in one application to compromise another application.http://secure.example.com/ and the application sets a session ID cookie with the domain ".example.com" when a user logs in.
setcookie("mySessionId", getSessionID(), 0, "/", ".example.com", true, true);
http://insecure.example.com/, and it contains a cross-site scripting vulnerability. Any user authenticated to http://secure.example.com that browses to http://insecure.example.com risks exposing their session cookie from http://secure.example.com.insecure.example.com to create its own overly broad cookie that overwrites the cookie from secure.example.com..example.com". This exposes the cookie to all web applications on the base domain and any sub-domains. Because cookies often carry sensitive information such as session identifiers, sharing cookies across applications can cause a vulnerability in one application to compromise another application.http://secure.example.com/ and the application sets a session ID cookie with the domain ".example.com" when a user logs in.
from django.http.response import HttpResponse
...
def view_method(request):
res = HttpResponse()
res.set_cookie("mySessionId", getSessionID(), domain=".example.com")
return res
...
http://insecure.example.com/, and it contains a cross-site scripting vulnerability. Any user authenticated to http://secure.example.com that browses to http://insecure.example.com risks exposing their session cookie from http://secure.example.com.insecure.example.com to create its own overly broad cookie that overwrites the cookie from secure.example.com..example.com". This exposes the cookie to all web applications on the base domain and any sub-domains. Because cookies often carry sensitive information such as session identifiers, sharing cookies across applications can cause a vulnerability in one application to compromise another application.http://secure.example.com/ and the application sets a session ID cookie with the domain ".example.com" when a user logs in.
Ok(Html(command)).withCookies(Cookie("sessionID", sessionID, domain = Some(".example.com")))
http://insecure.example.com/, and it contains a cross-site scripting vulnerability. Any user authenticated to http://secure.example.com that browses to http://insecure.example.com risks exposing their session cookie from http://secure.example.com.insecure.example.com to create its own overly broad cookie that overwrites the cookie from secure.example.com..example.com". This exposes the cookie to all web applications on the base domain and any sub-domains. Because cookies often carry sensitive information such as session identifiers, sharing cookies across applications can cause a vulnerability in one application to compromise another application.http://secure.example.com/ and the application sets a session ID cookie with the domain ".example.com" when a user logs in.
...
let properties = [
NSHTTPCookieDomain: ".example.com",
NSHTTPCookiePath: "/service",
NSHTTPCookieName: "foo",
NSHTTPCookieValue: "bar",
NSHTTPCookieSecure: true
]
let cookie : NSHTTPCookie? = NSHTTPCookie(properties:properties)
...
http://insecure.example.com/, and it contains a cross-site scripting vulnerability. Any user authenticated to http://secure.example.com that browses to http://insecure.example.com risks exposing their session cookie from http://secure.example.com.insecure.example.com to create its own overly broad cookie that overwrites the cookie from secure.example.com./"). This exposes the cookie to all web applications on the domain. Because cookies often carry sensitive information such as session identifiers, sharing cookies across applications can cause a vulnerability in one application to compromise another application.http://communitypages.example.com/MyForum and the application sets a session ID cookie with the path "/" when users log in to the forum. For example:
...
String path = '/';
Cookie cookie = new Cookie('sessionID', sessionID, path, maxAge, true, 'Strict');
...
http://communitypages.example.com/EvilSite and posts a link to this site on the forum. When a user of the forum clicks this link, the browser will send the cookie set by /MyForum to the application running at /EvilSite. By stealing the session ID, the attacker can compromise the account of any forum user that browsed to /EvilSite./EvilSite to create its own overly broad cookie that overwrites the cookie from /MyForum./", however, doing so exposes the cookie to all web applications on the same domain. Because cookies often carry sensitive information such as session identifiers, sharing cookies across applications can cause a vulnerability in one application to compromise another application.http://communitypages.example.com/MyForum and the application sets a session ID cookie with the path "/" when users log in to the forum.
HttpCookie cookie = new HttpCookie("sessionID", sessionID);
cookie.Path = "/";
http://communitypages.example.com/EvilSite and posts a link to this site on the forum. When a user of the forum clicks this link, the browser will send the cookie set by /MyForum to the application running at /EvilSite. By stealing the session ID, the attacker can compromise the account of any forum user that browsed to /EvilSite./EvilSite to create its own overly broad cookie that overwrites the cookie from /MyForum./"). This exposes the cookie to all web applications on the domain. Because cookies often carry sensitive information such as session identifiers, sharing cookies across applications can cause a vulnerability in one application to compromise another application.http://communitypages.example.com/MyForum and the application sets a session ID cookie with the path "/" when users log in to the forum.
cookie := http.Cookie{
Name: "sessionID",
Value: sID,
Expires: time.Now().AddDate(0, 0, 1),
Path: "/",
}
...
http://communitypages.example.com/EvilSite and posts a link to this site on the forum. When a forum user clicks this link, the browser sends the cookie set by /MyForum to the application running at /EvilSite. By stealing the session ID, the attacker can compromise the account of any forum user that browsed to /EvilSite./EvilSite to create its own overly broad cookie that overwrites the cookie from /MyForum./"). This exposes the cookie to all web applications on the domain. Because cookies often carry sensitive information such as session identifiers, sharing cookies across applications can cause a vulnerability in one application to compromise another application.http://communitypages.example.com/MyForum and the application sets a session ID cookie with the path "/" when users log in to the forum.
Cookie cookie = new Cookie("sessionID", sessionID);
cookie.setPath("/");
http://communitypages.example.com/EvilSite and posts a link to this site on the forum. When a user of the forum clicks this link, the browser will send the cookie set by /MyForum to the application running at /EvilSite. By stealing the session ID, the attacker can compromise the account of any forum user that browsed to /EvilSite./EvilSite to create its own overly broad cookie that overwrites the cookie from /MyForum./"). This exposes the cookie to all web applications on the domain. Because cookies often carry sensitive information such as session identifiers, sharing cookies across applications can cause a vulnerability in one application to compromise another application.http://communitypages.example.com/MyForum and the application sets a session ID cookie with the path "/" when users log in to the forum.
cookie_options = {};
cookie_options.path = '/';
...
res.cookie('important_cookie', info, cookie_options);
http://communitypages.example.com/EvilSite and posts a link to this site on the forum. When a user of the forum clicks this link, the browser will send the cookie set by /MyForum to the application running at /EvilSite. By stealing the session ID, the attacker can compromise the account of any forum user that browsed to /EvilSite./EvilSite to create its own overly broad cookie that overwrites the cookie from /MyForum./"). This exposes the cookie to all web applications on the domain. Because cookies often carry sensitive information such as session identifiers, sharing cookies across applications can cause a vulnerability in one application to compromise another application.http://communitypages.example.com/MyForum and the application sets a session ID cookie with the path "/" when users log in to the forum.
...
NSDictionary *cookieProperties = [NSDictionary dictionary];
...
[cookieProperties setValue:@"/" forKey:NSHTTPCookiePath];
...
NSHTTPCookie *cookie = [NSHTTPCookie cookieWithProperties:cookieProperties];
...
http://communitypages.example.com/EvilSite and posts a link to this site on the forum. When a user of the forum clicks this link, the browser will send the cookie set by /MyForum to the application running at /EvilSite. By stealing the session ID, the attacker can compromise the account of any forum user that browsed to /EvilSite./EvilSite to create its own overly broad cookie that overwrites the cookie from /MyForum./"). This exposes the cookie to all web applications on the domain. Because cookies often carry sensitive information such as session identifiers, sharing cookies across applications can cause a vulnerability in one application to compromise another application.http://communitypages.example.com/MyForum and the application sets a session ID cookie with the path "/" when users log in to the forum.
setcookie("mySessionId", getSessionID(), 0, "/", "communitypages.example.com", true, true);
http://communitypages.example.com/EvilSite and posts a link to this site on the forum. When a user of the forum clicks this link, the browser will send the cookie set by /MyForum to the application running at /EvilSite. By stealing the session ID, the attacker can compromise the account of any forum user that browsed to /EvilSite./EvilSite to create its own overly broad cookie that overwrites the cookie from /MyForum./"). This exposes the cookie to all web applications on the domain. Because cookies often carry sensitive information such as session identifiers, sharing cookies across applications can cause a vulnerability in one application to compromise another application.http://communitypages.example.com/MyForum and the application sets a session ID cookie with the path "/" when users log in to the forum.
from django.http.response import HttpResponse
...
def view_method(request):
res = HttpResponse()
res.set_cookie("sessionid", value) # Path defaults to "/"
return res
...
http://communitypages.example.com/EvilSite and posts a link to this site on the forum. When a user of the forum clicks this link, the browser will send the cookie set by /MyForum to the application running at /EvilSite. By stealing the session ID, the attacker can compromise the account of any forum user that browsed to /EvilSite./EvilSite to create its own overly broad cookie that overwrites the cookie from /MyForum./"). This exposes the cookie to all web applications on the domain. Because cookies often carry sensitive information such as session identifiers, sharing cookies across applications can cause a vulnerability in one application to compromise another application.http://communitypages.example.com/MyForum and the application sets a session ID cookie with the path "/" when users log in to the forum.
Ok(Html(command)).withCookies(Cookie("sessionID", sessionID, path = "/"))
http://communitypages.example.com/EvilSite and posts a link to this site on the forum. When a user of the forum clicks this link, the browser will send the cookie set by /MyForum to the application running at /EvilSite. By stealing the session ID, the attacker can compromise the account of any forum user that browsed to /EvilSite./EvilSite to create its own overly broad cookie that overwrites the cookie from /MyForum./"). This exposes the cookie to all web applications on the domain. Because cookies often carry sensitive information such as session identifiers, sharing cookies across applications can cause a vulnerability in one application to compromise another application.http://communitypages.example.com/MyForum and the application sets a session ID cookie with the path "/" when users log in to the forum.
...
let properties = [
NSHTTPCookieDomain: "www.example.com",
NSHTTPCookiePath: "/",
NSHTTPCookieName: "foo",
NSHTTPCookieValue: "bar",
NSHTTPCookieSecure: true
]
let cookie : NSHTTPCookie? = NSHTTPCookie(properties:properties)
...
http://communitypages.example.com/EvilSite and posts a link to this site on the forum. When a user of the forum clicks this link, the browser will send the cookie set by /MyForum to the application running at /EvilSite. By stealing the session ID, the attacker can compromise the account of any forum user that browsed to /EvilSite./EvilSite to create its own overly broad cookie that overwrites the cookie from /MyForum.
...
Integer maxAge = 60*60*24*365*10;
Cookie cookie = new Cookie('emailCookie', emailCookie, path, maxAge, true, 'Strict');
...
HttpCookie cookie = new HttpCookie("emailCookie", email);
cookie.Expires = DateTime.Now.AddYears(10);;
Cookie cookie = new Cookie("emailCookie", email);
cookie.setMaxAge(60*60*24*365*10);
...
NSDictionary *cookieProperties = [NSDictionary dictionary];
...
[cookieProperties setValue:[[NSDate date] dateByAddingTimeInterval:(60*60*24*365*10)] forKey:NSHTTPCookieExpires];
...
NSHTTPCookie *cookie = [NSHTTPCookie cookieWithProperties:cookieProperties];
...
setcookie("emailCookie", $email, time()+60*60*24*365*10);
from django.http.response import HttpResponse
...
def view_method(request):
res = HttpResponse()
res.set_cookie("emailCookie", email, expires=time()+60*60*24*365*10, secure=True, httponly=True)
return res
...
Ok(Html(command)).withCookies(Cookie("sessionID", sessionID, maxAge = Some(60*60*24*365*10)))
...
let properties = [
NSHTTPCookieDomain: "www.example.com",
NSHTTPCookiePath: "/service",
NSHTTPCookieName: "foo",
NSHTTPCookieValue: "bar",
NSHTTPCookieSecure: true,
NSHTTPCookieExpires : NSDate(timeIntervalSinceNow: (60*60*24*365*10))
]
let cookie : NSHTTPCookie? = NSHTTPCookie(properties:properties)
...
MyAccountActions and a page action method pageAction(). The pageAction() method is executed when visiting the page URL, and the server does not check for anti-CSRF tokens.
<apex:page controller="MyAccountActions" action="{!pageAction}">
...
</apex:page>
public class MyAccountActions {
...
public void pageAction() {
Map<String,String> reqParams = ApexPages.currentPage().getParameters();
if (params.containsKey('id')) {
Id id = reqParams.get('id');
Account acct = [SELECT Id,Name FROM Account WHERE Id = :id];
delete acct;
}
}
...
}
<img src="http://my-org.my.salesforce.com/apex/mypage?id=YellowSubmarine" height=1 width=1/>
RequestBuilder rb = new RequestBuilder(RequestBuilder.POST, "/new_user");
body = addToPost(body, new_username);
body = addToPost(body, new_passwd);
rb.sendRequest(body, new NewAccountCallback(callback));
RequestBuilder rb = new RequestBuilder(RequestBuilder.POST, "http://www.example.com/new_user");
body = addToPost(body, "attacker";
body = addToPost(body, "haha");
rb.sendRequest(body, new NewAccountCallback(callback));
example.com visits the malicious page while they have an active session on the site, they will unwittingly create an account for the attacker. This is a CSRF attack. It is possible because the application does not have a way to determine the provenance of the request. Any request could be a legitimate action chosen by the user or a faked action set up by an attacker. The attacker does not get to see the Web page that the bogus request generates, so the attack technique is only useful for requests that alter the state of the application.
<http auto-config="true">
...
<csrf disabled="true"/>
</http>
var req = new XMLHttpRequest();
req.open("POST", "/new_user", true);
body = addToPost(body, new_username);
body = addToPost(body, new_passwd);
req.send(body);
var req = new XMLHttpRequest();
req.open("POST", "http://www.example.com/new_user", true);
body = addToPost(body, "attacker");
body = addToPost(body, "haha");
req.send(body);
example.com visits the malicious page while she has an active session on the site, she will unwittingly create an account for the attacker. This is a CSRF attack. It is possible because the application does not have a way to determine the provenance of the request. Any request could be a legitimate action chosen by the user or a faked action set up by an attacker. The attacker does not get to see the Web page that the bogus request generates, so the attack technique is only useful for requests that alter the state of the application.
<form method="POST" action="/new_user" >
Name of new user: <input type="text" name="username">
Password for new user: <input type="password" name="user_passwd">
<input type="submit" name="action" value="Create User">
</form>
<form method="POST" action="http://www.example.com/new_user">
<input type="hidden" name="username" value="hacker">
<input type="hidden" name="user_passwd" value="hacked">
</form>
<script>
document.usr_form.submit();
</script>
example.com visits the malicious page while she has an active session on the site, she will unwittingly create an account for the attacker. This is a CSRF attack. It is possible because the application does not have a way to determine the provenance of the request. Any request could be a legitimate action chosen by the user or a faked action set up by an attacker. The attacker does not get to see the Web page that the bogus request generates, so the attack technique is only useful for requests that alter the state of the application.buyItem controller method.
+ nocsrf
POST /buyItem controllers.ShopController.buyItem
shop.com, she will unwittingly buy items for the attacker. This is a CSRF attack. It is possible because the application does not have a way to determine the provenance of the request. Any request could be a legitimate action chosen by the user or a faked action set up by an attacker. The attacker does not get to see the Web page that the bogus request generates, so the attack technique is only useful for requests that alter the state of the application.
<form method="POST" action="/new_user" >
Name of new user: <input type="text" name="username">
Password for new user: <input type="password" name="user_passwd">
<input type="submit" name="action" value="Create User">
</form>
<form method="POST" action="http://www.example.com/new_user">
<input type="hidden" name="username" value="hacker">
<input type="hidden" name="user_passwd" value="hacked">
</form>
<script>
document.usr_form.submit();
</script>
example.com visits the malicious page while she has an active session on the site, she will unwittingly create an account for the attacker. This is a CSRF attack. It is possible because the application does not have a way to determine the provenance of the request. Any request could be a legitimate action chosen by the user or a faked action set up by an attacker. The attacker does not get to see the Web page that the bogus request generates, so the attack technique is only useful for requests that alter the state of the application.
@GetMapping("/ai")
String generation(String userInput) {
return this.chatClient.prompt()
.user(userInput)
.call()
.content();
}
message, and displays it to the user.
const openai = new OpenAI({
apiKey: ...,
});
const chatCompletion = await openai.chat.completions.create(...);
message = res.choices[0].message.content
console.log(chatCompletion.choices[0].message.content)
val chatCompletionRequest = ChatCompletionRequest(
model = ModelId("gpt-3.5-turbo"),
messages = listOf(...)
)
val completion: ChatCompletion = openAI.chatCompletion(chatCompletionRequest)
response.getOutputStream().print(completion.choices[0].message)
message, and displays it to the user.
client = openai.OpenAI()
res = client.chat.completions.create(...)
message = res.choices[0].message.content
self.writeln(f"<p>{message}<\p>")
chatService.createCompletion(
text,
settings = CreateCompletionSettings(...)
).map(completion =>
val html = Html(completion.choices.head.text)
Ok(html) as HTML
)
...
...
DATA: BEGIN OF itab_employees,
eid TYPE employees-itm,
name TYPE employees-name,
END OF itab_employees,
itab LIKE TABLE OF itab_employees.
...
itab_employees-eid = '...'.
APPEND itab_employees TO itab.
SELECT *
FROM employees
INTO CORRESPONDING FIELDS OF TABLE itab_employees
FOR ALL ENTRIES IN itab
WHERE eid = itab-eid.
ENDSELECT.
...
response->append_cdata( 'Employee Name: ').
response->append_cdata( itab_employees-name ).
...
name are well-behaved, but it does nothing to prevent exploits if they are not. This code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.eid, from an HTTP request and displays it to the user.
...
eid = request->get_form_field( 'eid' ).
...
response->append_cdata( 'Employee ID: ').
response->append_cdata( eid ).
...
Example 1, this code operates correctly if eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.Example 1, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.Example 2, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.
stmt.sqlConnection = conn;
stmt.text = "select * from emp where id="+eid;
stmt.execute();
var rs:SQLResult = stmt.getResult();
if (null != rs) {
var name:String = String(rs.data[0]);
var display:TextField = new TextField();
display.htmlText = "Employee Name: " + name;
}
name are well-behaved, but it does nothing to prevent exploits if they are not. This code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.eid, from an HTTP request and displays it to the user.
var params:Object = LoaderInfo(this.root.loaderInfo).parameters;
var eid:String = String(params["eid"]);
...
var display:TextField = new TextField();
display.htmlText = "Employee ID: " + eid;
...
Example 1, this code operates correctly if eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.Example 1, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.Example 2, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.
...
variable = Database.query('SELECT Name FROM Contact WHERE id = ID');
...
<div onclick="this.innerHTML='Hello {!variable}'">Click me!</div>
name are well defined like just alphanumeric characters, but does nothing to check for malicious data. Even read from a database, the value should be properly validated because the content of the database can be originated from user-supplied data. This way, an attacker can have malicious commands executed in the user's web browser without the need to interact with the victim like in Reflected XSS. This type of attack, known as Stored XSS (or Persistent), can be very hard to detect since the data is indirectly provided to the vulnerable function and also have a higher impact due to the possibility to affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.username, and displays it to the user.
<script>
document.write('{!$CurrentPage.parameters.username}')
</script>
username contains metacharacters or source code, it will be executed by the web browser.Example 1, the database or other data store can provide dangerous data to the application that will be included in dynamic content. From the attacker's perspective, the best place to store malicious content is an area accessible to all users specially those with elevated privileges, who are more likely to handle sensitive information or perform critical operations.Example 2, data is read from the HTTP request and reflected back in the HTTP response. Reflected XSS occurs when an attacker can have dangerous content delivered to a vulnerable web application and then reflected back to the user and execute by his browser. The most common mechanism to deliver malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to the victim. URLs crafted this way are the core of many phishing schemes, where the attacker lures the victim to visit the URL. After the site reflects the content back to the user, it is executed and can perform several actions like forward private sensitive information, execute unauthorized operations on the victim computer etc.
<script runat="server">
...
string query = "select * from emp where id=" + eid;
sda = new SqlDataAdapter(query, conn);
DataTable dt = new DataTable();
sda.Fill(dt);
string name = dt.Rows[0]["Name"];
...
EmployeeName.Text = name;
</script>
EmployeeName is a form control defined as follows:Example 2: The following ASP.NET code segment is functionally equivalent to
<form runat="server">
...
<asp:Label id="EmployeeName" runat="server">
...
</form>
Example 1, but implements all of the form elements programmatically.
protected System.Web.UI.WebControls.Label EmployeeName;
...
string query = "select * from emp where id=" + eid;
sda = new SqlDataAdapter(query, conn);
DataTable dt = new DataTable();
sda.Fill(dt);
string name = dt.Rows[0]["Name"];
...
EmployeeName.Text = name;
name are well-behaved, but they do nothing to prevent exploits if they are not. This code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.
<script runat="server">
...
EmployeeID.Text = Login.Text;
...
</script>
Login and EmployeeID are form controls defined as follows:Example 4: The following ASP.NET code segment shows the programmatic way to implement
<form runat="server">
<asp:TextBox runat="server" id="Login"/>
...
<asp:Label runat="server" id="EmployeeID"/>
</form>
Example 3.
protected System.Web.UI.WebControls.TextBox Login;
protected System.Web.UI.WebControls.Label EmployeeID;
...
EmployeeID.Text = Login.Text;
Example 1 and Example 2, these examples operate correctly if Login contains only standard alphanumeric text. If Login has a value that includes metacharacters or source code, then the code will be executed by the web browser as it displays the HTTP response.Example 1 and Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.Example 3 and Example 4, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.
...
EXEC SQL
SELECT NAME
INTO :ENAME
FROM EMPLOYEE
WHERE ID = :EID
END-EXEC.
EXEC CICS
WEB SEND
FROM(ENAME)
...
END-EXEC.
...
ENAME are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of ENAME is read from a database, whose contents are apparently managed by the application. However, if the value of ENAME originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Stored XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.EID, from an HTML form and displays it to the user.
...
EXEC CICS
WEB READ
FORMFIELD(ID)
VALUE(EID)
...
END-EXEC.
EXEC CICS
WEB SEND
FROM(EID)
...
END-EXEC.
...
Example 1, this code operates correctly if EID contains only standard alphanumeric text. If EID has a value that includes metacharacters or source code, then the code will be executed by the web browser as it displays the HTTP response.Example 1, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Stored XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker might perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.Example 2, data is read directly from the HTML Form and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.
<cfquery name="matchingEmployees" datasource="cfsnippets">
SELECT name
FROM Employees
WHERE eid = '#Form.eid#'
</cfquery>
<cfoutput>
Employee Name: #name#
</cfoutput>
name are well-behaved, but it does nothing to prevent exploits if they are not. This code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.eid, from a web form and displays it to the user.
<cfoutput>
Employee ID: #Form.eid#
</cfoutput>
Example 1, this code operates correctly if Form.eid contains only standard alphanumeric text. If Form.eid has a value that includes metacharacters or source code, then the code will be executed by the web browser as it displays the HTTP response.Example 1, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.Example 2, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.user, from an HTTP request and displays it to the user.
func someHandler(w http.ResponseWriter, r *http.Request){
r.parseForm()
user := r.FormValue("user")
...
fmt.Fprintln(w, "Username is: ", user)
}
user contains only standard alphanumeric text. If user has a value that includes metacharacters or source code, then the code will be executed by the web browser as it displays the HTTP response.
func someHandler(w http.ResponseWriter, r *http.Request){
...
row := db.QueryRow("SELECT name FROM users WHERE id =" + userid)
err := row.Scan(&name)
...
fmt.Fprintln(w, "Username is: ", name)
}
Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker can execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack affects multiple users. XSS began in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker can perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.
<%...
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("select * from emp where id="+eid);
if (rs != null) {
rs.next();
String name = rs.getString("name");
}
%>
Employee Name: <%= name %>
name are well-behaved, but it does nothing to prevent exploits if they are not. This code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.eid, from an HTTP request and displays it to the user.
<% String eid = request.getParameter("eid"); %>
...
Employee ID: <%= eid %>
Example 1, this code operates correctly if eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.
...
WebView webview = (WebView) findViewById(R.id.webview);
webview.getSettings().setJavaScriptEnabled(true);
String url = this.getIntent().getExtras().getString("url");
webview.loadUrl(url);
...
url starts with javascript:, JavaScript code that follows executes within the context of the web page inside WebView.Example 1, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.Example 2, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 3, a source outside the application stores dangerous data in a database or other data store, and the dangerous data is subsequently read back into the application as trusted data and included in dynamic content.
var http = require('http');
...
function listener(request, response){
connection.query('SELECT * FROM emp WHERE eid="' + eid + '"', function(err, rows){
if (!err && rows.length > 0){
response.write('<p>Welcome, ' + rows[0].name + '!</p>');
}
...
});
...
}
...
http.createServer(listener).listen(8080);
name are well-behaved, but it does nothing to prevent exploits if they are not. This code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.eid, from an HTTP request and displays it to the user.
var http = require('http');
var url = require('url');
...
function listener(request, response){
var eid = url.parse(request.url, true)['query']['eid'];
if (eid !== undefined){
response.write('<p>Welcome, ' + eid + '!</p>');
}
...
}
...
http.createServer(listener).listen(8080);
Example 1, this code operates correctly if eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.Example 1, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.Example 2, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.
...
val stmt: Statement = conn.createStatement()
val rs: ResultSet = stmt.executeQuery("select * from emp where id=$eid")
rs.next()
val name: String = rs.getString("name")
...
val out: ServletOutputStream = response.getOutputStream()
out.print("Employee Name: $name")
...
out.close()
...
name are well-behaved, but it does nothing to prevent exploits if they are not. This code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.eid, from an HTTP servlet request, then displays the value back to the user in the servlet's response.
val eid: String = request.getParameter("eid")
...
val out: ServletOutputStream = response.getOutputStream()
out.print("Employee ID: $eid")
...
out.close()
...
Example 1, this code operates correctly if eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.
...
val webview = findViewById<View>(R.id.webview) as WebView
webview.settings.javaScriptEnabled = true
val url = this.intent.extras!!.getString("url")
webview.loadUrl(url)
...
url starts with javascript:, JavaScript code that follows executes within the context of the web page inside WebView.Example 1, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.Example 2, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 3, a source outside the application stores dangerous data in a database or other data store, and the dangerous data is subsequently read back into the application as trusted data and included in dynamic content.name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.myapp://input_to_the_application). The untrusted data in the URL is then used to render HTML output in a UIWebView component.
...
- (BOOL)application:(UIApplication *)application handleOpenURL:(NSURL *)url {
UIWebView *webView;
NSString *partAfterSlashSlash = [[url host] stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
webView = [[UIWebView alloc] initWithFrame:CGRectMake(0.0,0.0,360.0, 480.0)];
[webView loadHTMLString:partAfterSlashSlash baseURL:nil]
...
Example 1, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.Example 2, data is read directly from a custom URL scheme and reflected back in the content of a UIWebView response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable iOS application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a custom scheme URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable app. After the app reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.
<?php...
$con = mysql_connect($server,$user,$password);
...
$result = mysql_query("select * from emp where id="+eid);
$row = mysql_fetch_array($result)
echo 'Employee name: ', mysql_result($row,0,'name');
...
?>
name are well-behaved, but it does nothing to prevent exploits if they are not. This code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.eid, from an HTTP request and displays it to the user.
<?php
$eid = $_GET['eid'];
...
?>
...
<?php
echo "Employee ID: $eid";
?>
Example 1, this code operates correctly if eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.Example 1, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.Example 2, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.
...
SELECT ename INTO name FROM emp WHERE id = eid;
HTP.htmlOpen;
HTP.headOpen;
HTP.title ('Employee Information');
HTP.headClose;
HTP.bodyOpen;
HTP.br;
HTP.print('< b >Employee Name: ' || name || '</ b >');
HTP.br;
HTP.bodyClose;
HTP.htmlClose;
...
name are well-behaved, but it does nothing to prevent exploits if they are not. This code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.eid, from an HTTP request and displays it to the user.
...
-- Assume QUERY_STRING looks like EID=EmployeeID
eid := SUBSTR(OWA_UTIL.get_cgi_env('QUERY_STRING'), 5);
HTP.htmlOpen;
HTP.headOpen;
HTP.title ('Employee Information');
HTP.headClose;
HTP.bodyOpen;
HTP.br;
HTP.print('< b >Employee ID: ' || eid || '</ b >');
HTP.br;
HTP.bodyClose;
HTP.htmlClose;
...
Example 1, this code operates correctly if eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.Example 1, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.Example 2, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.eid, from an HTTP request and displays it to the user.
req = self.request() # fetch the request object
eid = req.field('eid',None) # tainted request message
...
self.writeln("Employee ID:" + eid)
eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.
...
cursor.execute("select * from emp where id="+eid)
row = cursor.fetchone()
self.writeln('Employee name: ' + row["emp"]')
...
Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.
...
rs = conn.exec_params("select * from emp where id=?", eid)
...
Rack::Response.new.finish do |res|
...
rs.each do |row|
res.write("Employee name: #{escape(row['name'])}")
...
end
end
...
name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.eid, from an HTTP request and displays it to the user.
eid = req.params['eid'] #gets request parameter 'eid'
Rack::Response.new.finish do |res|
...
res.write("Employee ID: #{eid}")
end
Example 1, the code in this example operates correctly if eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code will be executed by the web browser as it displays the HTTP response.Rack::Request#params() as in Example 2, this sees both GET and POST parameters, so may be vulnerable to various types of attacks other than just having the malicious code appended to the URL.Example 1, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.Example 2, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.eid, from a database query and displays it to the user.
def getEmployee = Action { implicit request =>
val employee = getEmployeeFromDB()
val eid = employee.id
if (employee == Null) {
val html = Html(s"Employee ID ${eid} not found")
Ok(html) as HTML
}
...
}
name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.
...
let webView : WKWebView
let inputTextField : UITextField
webView.loadHTMLString(inputTextField.text, baseURL:nil)
...
inputTextField contains only standard alphanumeric text. If the text within inputTextField includes metacharacters or source code, then the input may be executed as code by the web browser as it displays the HTTP response.myapp://input_to_the_application). The untrusted data in the URL is then used to render HTML output in a UIWebView component.
...
func application(app: UIApplication, openURL url: NSURL, options: [String : AnyObject]) -> Bool {
...
let name = getQueryStringParameter(url.absoluteString, "name")
let html = "Hi \(name)"
let webView = UIWebView()
webView.loadHTMLString(html, baseURL:nil)
...
}
func getQueryStringParameter(url: String?, param: String) -> String? {
if let url = url, urlComponents = NSURLComponents(string: url), queryItems = (urlComponents.queryItems as? [NSURLQueryItem]) {
return queryItems.filter({ (item) in item.name == param }).first?.value!
}
return nil
}
...
Example 1, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.Example 2, data is read directly from a user-controllable UI component and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 3, a source outside the target application makes a URL request using the target application's custom URL scheme, and unvalidated data from the URL request subsequently read back into the application as trusted data and included in dynamic content.
...
eid = Request("eid")
strSQL = "Select * from emp where id=" & eid
objADORecordSet.Open strSQL, strConnect, adOpenDynamic, adLockOptimistic, adCmdText
while not objRec.EOF
Response.Write "Employee Name:" & objADORecordSet("name")
objADORecordSet.MoveNext
Wend
...
name are well-behaved, but it does nothing to prevent exploits if they are not. This code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.eid, from an HTTP request and displays it to the user.
...
eid = Request("eid")
Response.Write "Employee ID:" & eid & "<br/>"
..
Example 1, this code operates correctly if eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.Example 1, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.Example 2, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.cl_http_utility=>escape_html, will prevent some, but not all cross-site scripting attacks. Depending on the context in which the data appear, characters beyond the basic <, >, &, and " that are HTML-encoded and those beyond <, >, &, ", and ' that are XML-encoded may take on meta-meaning. Relying on such encoding function modules is equivalent to using a weak deny list to prevent cross-site scripting and might allow an attacker to inject malicious code that will be executed in the browser. Because accurately identifying the context in which the data appear statically is not always possible, the Fortify Secure Coding Rulepacks report cross-site scripting findings even when encoding is applied and presents them as Cross-Site Scripting: Poor Validation issues.eid, from an HTTP request, HTML-encodes it, and displays it to the user.
...
eid = request->get_form_field( 'eid' ).
...
CALL METHOD cl_http_utility=>escape_html
EXPORTING
UNESCAPED = eid
KEEP_NUM_CHAR_REF = '-'
RECEIVING
ESCAPED = e_eid.
...
response->append_cdata( 'Employee ID: ').
response->append_cdata( e_eid ).
...
eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.
...
DATA: BEGIN OF itab_employees,
eid TYPE employees-itm,
name TYPE employees-name,
END OF itab_employees,
itab LIKE TABLE OF itab_employees.
...
itab_employees-eid = '...'.
APPEND itab_employees TO itab.
SELECT *
FROM employees
INTO CORRESPONDING FIELDS OF TABLE itab_employees
FOR ALL ENTRIES IN itab
WHERE eid = itab-eid.
ENDSELECT.
...
CALL METHOD cl_http_utility=>escape_html
EXPORTING
UNESCAPED = itab_employees-name
KEEP_NUM_CHAR_REF = '-'
RECEIVING
ESCAPED = e_name.
...
response->append_cdata( 'Employee Name: ').
response->append_cdata( e_name ).
...
Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.eid, from an HTTP request, HTML-encodes it, and displays it to the user.
var params:Object = LoaderInfo(this.root.loaderInfo).parameters;
var eid:String = String(params["eid"]);
...
var display:TextField = new TextField();
display.htmlText = "Employee ID: " + escape(eid);
...
eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.
stmt.sqlConnection = conn;
stmt.text = "select * from emp where id="+eid;
stmt.execute();
var rs:SQLResult = stmt.getResult();
if (null != rs) {
var name:String = String(rs.data[0]);
var display:TextField = new TextField();
display.htmlText = "Employee Name: " + escape(name);
}
Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.
...
variable = Database.query('SELECT Name FROM Contact WHERE id = ID');
...
<div onclick="this.innerHTML='Hello {!HTMLENCODE(variable)}'">Click me!</div>
HTMLENCODE, does not properly validate the data provided by the database and is vulnerable to XSS. This happens because the variable content is parsed by different mechanisms (HTML and Javascript parsers), therfore neeeds to be encoded two times. This way, an attacker can have malicious commands executed in the user's web browser without the need to interact with the victim like in Reflected XSS. This type of attack, known as Stored XSS (or Persistent), can be very hard to detect since the data is indirectly provided to the vulnerable function and also have a higher impact due to the possibility to affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.username, and displays it to the user.
<script>
document.write('{!HTMLENCODE($CurrentPage.parameters.username)}')
</script>
username contains metacharacters or source code, it will be executed by the web browser. Also in this example the usage of HTMLENCODE is not enough to prevent the XSS attack since the variable is processed by the Javascript parser.Example 1, the database or other data store can provide dangerous data to the application that will be included in dynamic content. From the attacker's perspective, the best place to store malicious content is an area accessible to all users specially those with elevated privileges, who are more likely to handle sensitive information or perform critical operations.Example 2, data is read from the HTTP request and reflected back in the HTTP response. Reflected XSS occurs when an attacker can have dangerous content delivered to a vulnerable web application and then reflected back to the user and execute by his browser. The most common mechanism to deliver malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to the victim. URLs crafted this way are the core of many phishing schemes, where the attacker lures the victim to visit the URL. After the site reflects the content back to the user, it is executed and can perform several actions like forward private sensitive information, execute unauthorized operations on the victim computer etc.
<script runat="server">
...
EmployeeID.Text = Server.HtmlEncode(Login.Text);
...
</script>
Login and EmployeeID are form controls defined as follows:Example 2: The following ASP.NET code segment implements the same functionality as in
<form runat="server">
<asp:TextBox runat="server" id="Login"/>
...
<asp:Label runat="server" id="EmployeeID"/>
</form>
Example 1, albeit programmatically.
protected System.Web.UI.WebControls.TextBox Login;
protected System.Web.UI.WebControls.Label EmployeeID;
...
EmployeeID.Text = Server.HtmlEncode(Login.Text);
Login contains only standard alphanumeric text. If Login has a value that includes metacharacters or source code, then the code will be executed by the web browser as it displays the HTTP response.
<script runat="server">
...
string query = "select * from emp where id=" + eid;
sda = new SqlDataAdapter(query, conn);
DataTable dt = new DataTable();
sda.Fill(dt);
string name = dt.Rows[0]["Name"];
...
EmployeeName.Text = Server.HtmlEncode(name);
</script>
EmployeeName is a form control defined as follows:Example 4: Likewise, the following ASP.NET code segment is functionally equivalent to
<form runat="server">
...
<asp:Label id="EmployeeName" runat="server">
...
</form>
Example 3, but implements all of the form elements programmatically.
protected System.Web.UI.WebControls.Label EmployeeName;
...
string query = "select * from emp where id=" + eid;
sda = new SqlDataAdapter(query, conn);
DataTable dt = new DataTable();
sda.Fill(dt);
string name = dt.Rows[0]["Name"];
...
EmployeeName.Text = Server.HtmlEncode(name);
Example 1 and Example 2, these code segments perform correctly when the values of name are well-behaved, but they do nothing to prevent exploits if they are not. Again, these code examples can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1 and Example 2, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 3 and Example 4, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.text parameter, from an HTTP request, HTML-encodes it, and displays it in an alert box in between script tags.
"<script>alert('<CFOUTPUT>HTMLCodeFormat(#Form.text#)</CFOUTPUT>')</script>";
text contains only standard alphanumeric text. If text has a single quote, a round bracket and a semicolon, it ends the alert textbox thereafter the code will be executed.Example 1, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.user, from an HTTP request and displays it to the user.
func someHandler(w http.ResponseWriter, r *http.Request){
r.parseForm()
user := r.FormValue("user")
...
fmt.Fprintln(w, "Username is: ", html.EscapeString(user))
}
user contains only standard alphanumeric text. If user has a value that includes metacharacters or source code, then the code will be executed by the web browser as it displays the HTTP response.
func someHandler(w http.ResponseWriter, r *http.Request){
...
row := db.QueryRow("SELECT name FROM users WHERE id =" + userid)
err := row.Scan(&name)
...
fmt.Fprintln(w, "Username is: ", html.EscapeString(name))
}
Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker can execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack affects multiple users. XSS began in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker can perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.<c:out/> tag with the escapeXml="true" attribute (the default behavior), prevents some, but not all cross-site scripting attacks. Depending on the context in which the data appear, characters beyond the basic <, >, &, and " that are HTML-encoded and those beyond <, >, &, ", and ' that are XML-encoded might take on meta-meaning. Relying on such encoding constructs is equivalent to using a weak deny list to prevent cross-site scripting and might allow an attacker to inject malicious code that will be executed in the browser. Because accurately identifying the context in which the data appear statically is not always possible, Fortify Static Code Analyzer reports cross-site scripting findings even when encoding is applied and presents them as Cross-Site Scripting: Poor Validation issues.eid, from an HTTP request and displays it to the user via the <c:out/> tag.
Employee ID: <c:out value="${param.eid}"/>
eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.<c:out/> tag.
<%...
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("select * from emp where id="+eid);
if (rs != null) {
rs.next();
String name = rs.getString("name");
}
%>
Employee Name: <c:out value="${name}"/>
Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.
...
WebView webview = (WebView) findViewById(R.id.webview);
webview.getSettings().setJavaScriptEnabled(true);
String url = this.getIntent().getExtras().getString("url");
webview.loadUrl(URLEncoder.encode(url));
...
url starts with javascript:, JavaScript code that follows executes within the context of the web page inside WebView.Example 1, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.Example 3, a source outside the application stores dangerous data in a database or other data store, and the dangerous data is subsequently read back into the application as trusted data and included in dynamic content.eid, from an HTTP request, escapes it, and displays it to the user.
<SCRIPT>
var pos=document.URL.indexOf("eid=")+4;
document.write(escape(document.URL.substring(pos,document.URL.length)));
</SCRIPT>
eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.<c:out/> tag with the escapeXml="true" attribute (the default behavior), prevents some, but not all cross-site scripting attacks. Depending on the context in which the data appear, characters beyond the basic <, >, &, and " that are HTML-encoded and those beyond <, >, &, ", and ' that are XML-encoded might take on meta-meaning. Relying on such encoding constructs is equivalent to using a weak deny list to prevent cross-site scripting and might allow an attacker to inject malicious code that will be executed in the browser. Because accurately identifying the context in which the data appear statically is not always possible, Fortify Static Code Analyzer reports cross-site scripting findings even when encoding is applied and presents them as Cross-Site Scripting: Poor Validation issues.eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.
...
val webview = findViewById<View>(R.id.webview) as WebView
webview.settings.javaScriptEnabled = true
val url = this.intent.extras!!.getString("url")
webview.loadUrl(URLEncoder.encode(url))
...
url starts with javascript:, JavaScript code that follows executes within the context of the web page inside WebView.Example 1, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.Example 3, a source outside the application stores dangerous data in a database or other data store, and the dangerous data is subsequently read back into the application as trusted data and included in dynamic content.myapp://input_to_the_application). The untrusted data in the URL is then used to render HTML output in a UIWebView component.
...
- (BOOL)application:(UIApplication *)application handleOpenURL:(NSURL *)url {
...
UIWebView *webView;
NSString *partAfterSlashSlash = [[url host] stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSString *htmlPage = [NSString stringWithFormat: @"%@/%@/%@", @"...<input type=text onclick=\"callFunction('",
[DefaultEncoder encodeForHTML:partAfterSlashSlash],
@"')\" />"];
webView = [[UIWebView alloc] initWithFrame:CGRectMake(0.0,0.0,360.0, 480.0)];
[webView loadHTMLString:htmlPage baseURL:nil];
...
Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database and is HTML encoded. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. The attacker supplied exploit could bypass encoded characters or place input in a context which is not effected by HTML encoding. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1, data is read directly from a custom URL scheme and reflected back in the content of a UIWebView response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable iOS application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a custom scheme URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable app. After the app reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.htmlspecialchars() or htmlentities(), will prevent some, but not all cross-site scripting attacks. Depending on the context in which the data appear, characters beyond the basic <, >, &, and " that are HTML-encoded and those beyond <, >, &, ", and ' (only when ENT_QUOTES is set) that are XML-encoded may take on meta-meaning. Relying on such encoding functions is equivalent to using a weak deny list to prevent cross-site scripting and might allow an attacker to inject malicious code that will be executed in the browser. Because accurately identifying the context in which the data appear statically is not always possible, the Fortify Secure Coding Rulepacks reports cross-site scripting findings even when encoding is applied and presents them as Cross-Site Scripting: Poor Validation issues.text parameter, from an HTTP request, HTML-encodes it, and displays it in an alert box in between script tags.
<?php
$var=$_GET['text'];
...
$var2=htmlspecialchars($var);
echo "<script>alert('$var2')</script>";
?>
text contains only standard alphanumeric text. If text has a single quote, a round bracket and a semicolon, it ends the alert textbox thereafter the code will be executed.Example 1, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.eid, from an HTTP request, URL-encodes it, and displays it to the user.
...
-- Assume QUERY_STRING looks like EID=EmployeeID
eid := SUBSTR(OWA_UTIL.get_cgi_env('QUERY_STRING'), 5);
HTP.htmlOpen;
HTP.headOpen;
HTP.title ('Employee Information');
HTP.headClose;
HTP.bodyOpen;
HTP.br;
HTP.print('< b >Employee ID: ' || HTMLDB_UTIL.url_encode(eid) || '</ b >');
HTP.br;
HTP.bodyClose;
HTP.htmlClose;
...
eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.
...
SELECT ename INTO name FROM emp WHERE id = eid;
HTP.htmlOpen;
HTP.headOpen;
HTP.title ('Employee Information');
HTP.headClose;
HTP.bodyOpen;
HTP.br;
HTP.print('< b >Employee Name: ' || HTMLDB_UTIL.url_encode(name) || '</ b >');
HTP.br;
HTP.bodyClose;
HTP.htmlClose;
...
Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.eid, from an HTTP request, HTML-encodes it, and displays it to the user.
req = self.request() # fetch the request object
eid = req.field('eid',None) # tainted request message
...
self.writeln("Employee ID:" + escape(eid))
eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.
...
cursor.execute("select * from emp where id="+eid)
row = cursor.fetchone()
self.writeln('Employee name: ' + escape(row["emp"]))
...
Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.eid, from an HTTP request, HTML-encodes it, and displays it to the user.
eid = req.params['eid'] #gets request parameter 'eid'
Rack::Response.new.finish do |res|
...
res.write("Employee ID: #{eid}")
end
eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.Rack::Request#params() as in Example 1, this sees both GET and POST parameters, so may be vulnerable to various types of attacks other than just having the malicious code appended to the URL.
...
rs = conn.exec_params("select * from emp where id=?", eid)
...
Rack::Response.new.finish do |res|
...
rs.each do |row|
res.write("Employee name: #{escape(row['name'])}")
...
end
end
...
Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation of all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.eid, from an HTTP request and displays it to the user.
def getEmployee = Action { implicit request =>
var eid = request.getQueryString("eid")
eid = StringEscapeUtils.escapeHtml(eid); // insufficient validation
val employee = getEmployee(eid)
if (employee == Null) {
val html = Html(s"Employee ID ${eid} not found")
Ok(html) as HTML
}
...
}
eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.myapp://input_to_the_application). The untrusted data in the URL is then used to render HTML output in a UIWebView component.
...
func application(app: UIApplication, openURL url: NSURL, options: [String : AnyObject]) -> Bool {
...
let name = getQueryStringParameter(url.absoluteString, "name")
let html = "Hi \(name)"
let webView = UIWebView()
webView.loadHTMLString(html, baseURL:nil)
...
}
func getQueryStringParameter(url: String?, param: String) -> String? {
if let url = url, urlComponents = NSURLComponents(string: url), queryItems = (urlComponents.queryItems as? [NSURLQueryItem]) {
return queryItems.filter({ (item) in item.name == param }).first?.value!
}
return nil
}
...
Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database and is HTML encoded. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. The attacker supplied exploit could bypass encoded characters or place input in a context which is not effected by HTML encoding. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.
...
let webView : WKWebView
let inputTextField : UITextField
webView.loadHTMLString(inputTextField.text, baseURL:nil)
...
inputTextField contains only standard alphanumeric text. If the text within inputTextField includes metacharacters or source code, then the input may be executed as code by the web browser as it displays the HTTP response.Example 1, data is read directly from a custom URL scheme and reflected back in the content of a UIWebView response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable iOS application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a custom scheme URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable app. After the app reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.Example 3, a source outside the target application makes a URL request using the target application's custom URL scheme, and unvalidated data from the URL request subsequently read back into the application as trusted data and included in dynamic content.eid, from an HTTP request, HTML-encodes it, and displays it to the user.
...
eid = Request("eid")
Response.Write "Employee ID:" & Server.HTMLEncode(eid) & "<br/>"
..
eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.
...
eid = Request("eid")
strSQL = "Select * from emp where id=" & eid
objADORecordSet.Open strSQL, strConnect, adOpenDynamic, adLockOptimistic, adCmdText
while not objRec.EOF
Response.Write "Employee Name:" & Server.HTMLEncode(objADORecordSet("name"))
objADORecordSet.MoveNext
Wend
...
Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.eid, from an HTTP request and displays it to the user.
...
eid = request->get_form_field( 'eid' ).
...
response->append_cdata( 'Employee ID: ').
response->append_cdata( eid ).
...
eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.
...
DATA: BEGIN OF itab_employees,
eid TYPE employees-itm,
name TYPE employees-name,
END OF itab_employees,
itab LIKE TABLE OF itab_employees.
...
itab_employees-eid = '...'.
APPEND itab_employees TO itab.
SELECT *
FROM employees
INTO CORRESPONDING FIELDS OF TABLE itab_employees
FOR ALL ENTRIES IN itab
WHERE eid = itab-eid.
ENDSELECT.
...
response->append_cdata( 'Employee Name: ').
response->append_cdata( itab_employees-name ).
...
Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.eid, from an HTTP request and displays it to the user.
var params:Object = LoaderInfo(this.root.loaderInfo).parameters;
var eid:String = String(params["eid"]);
...
var display:TextField = new TextField();
display.htmlText = "Employee ID: " + eid;
...
eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.
stmt.sqlConnection = conn;
stmt.text = "select * from emp where id="+eid;
stmt.execute();
var rs:SQLResult = stmt.getResult();
if (null != rs) {
var name:String = String(rs.data[0]);
var display:TextField = new TextField();
display.htmlText = "Employee Name: " + name;
}
Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.username, and displays it to the user.
<script>
document.write('{!$CurrentPage.parameters.username}')
</script>
username contains metacharacters or source code, it will be executed by the web browser.
...
variable = Database.query('SELECT Name FROM Contact WHERE id = ID');
...
<div onclick="this.innerHTML='Hello {!variable}'">Click me!</div>
Example 1, this code behaves correctly when the values of name are well defined like just alphanumeric characters, but does nothing to check for malicious data. Even read from a database, the value should be properly validated because the content of the database can be originated from user-supplied data. This way, an attacker can have malicious commands executed in the user's web browser without the need to interact with the victim like in Reflected XSS. This type of attack, known as Stored XSS (or Persistent), can be very hard to detect since the data is indirectly provided to the vulnerable function and also have a higher impact due to the possibility to affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1, data is read from the HTTP request and reflected back in the HTTP response. Reflected XSS occurs when an attacker can have dangerous content delivered to a vulnerable web application and then reflected back to the user and execute by his browser. The most common mechanism to deliver malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to the victim. URLs crafted this way are the core of many phishing schemes, where the attacker lures the victim to visit the URL. After the site reflects the content back to the user, it is executed and can perform several actions like forward private sensitive information, execute unauthorized operations on the victim computer etc.Example 2, the database or other data store can provide dangerous data to the application that will be included in dynamic content. From the attacker's perspective, the best place to store malicious content is an area accessible to all users specially those with elevated privileges, who are more likely to handle sensitive information or perform critical operations.
<script runat="server">
...
EmployeeID.Text = Login.Text;
...
</script>
Login and EmployeeID are form controls defined as follows:Example 2: The following ASP.NET code segment shows the programmatic way to implement
<form runat="server">
<asp:TextBox runat="server" id="Login"/>
...
<asp:Label runat="server" id="EmployeeID"/>
</form>
Example 1.
protected System.Web.UI.WebControls.TextBox Login;
protected System.Web.UI.WebControls.Label EmployeeID;
...
EmployeeID.Text = Login.Text;
Login contains only standard alphanumeric text. If Login has a value that includes metacharacters or source code, then the code will be executed by the web browser as it displays the HTTP response.
<script runat="server">
...
string query = "select * from emp where id=" + eid;
sda = new SqlDataAdapter(query, conn);
DataTable dt = new DataTable();
sda.Fill(dt);
string name = dt.Rows[0]["Name"];
...
EmployeeName.Text = name;
</script>
EmployeeName is a form control defined as follows:Example 4: The following ASP.NET code segment is functionally equivalent to
<form runat="server">
...
<asp:Label id="EmployeeName" runat="server">
...
</form>
Example 3, but implements all of the form elements programmatically.
protected System.Web.UI.WebControls.Label EmployeeName;
...
string query = "select * from emp where id=" + eid;
sda = new SqlDataAdapter(query, conn);
DataTable dt = new DataTable();
sda.Fill(dt);
string name = dt.Rows[0]["Name"];
...
EmployeeName.Text = name;
Example 1 and Example 2, these code examples function correctly when the values of name are well-behaved, but they nothing to prevent exploits if the values are not. Again, these can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1 and Example 2, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 3 and Example 4, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.EID, from an HTML form and displays it to the user.
...
EXEC CICS
WEB READ
FORMFIELD(ID)
VALUE(EID)
...
END-EXEC.
EXEC CICS
WEB SEND
FROM(EID)
...
END-EXEC.
...
EID contains only standard alphanumeric text. If EID has a value that includes metacharacters or source code, then the code will be executed by the web browser as it displays the HTTP response.
...
EXEC SQL
SELECT NAME
INTO :ENAME
FROM EMPLOYEE
WHERE ID = :EID
END-EXEC.
EXEC CICS
WEB SEND
FROM(ENAME)
...
END-EXEC.
...
Example 1, this code functions correctly when the values of ENAME are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of ENAME is read from a database, whose contents are apparently managed by the application. However, if the value of ENAME originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Stored XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1, data is read directly from the HTML Form and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Stored XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker might perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.eid, from a web form and displays it to the user.
<cfoutput>
Employee ID: #Form.eid#
</cfoutput>
Form.eid contains only standard alphanumeric text. If Form.eid has a value that includes metacharacters or source code, then the code will be executed by the web browser as it displays the HTTP response.
<cfquery name="matchingEmployees" datasource="cfsnippets">
SELECT name
FROM Employees
WHERE eid = '#Form.eid#'
</cfquery>
<cfoutput>
Employee Name: #name#
</cfoutput>
Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.user, from an HTTP request and displays it to the user.
func someHandler(w http.ResponseWriter, r *http.Request){
r.parseForm()
user := r.FormValue("user")
...
fmt.Fprintln(w, "Username is: ", user)
}
user contains only standard alphanumeric text. If user has a value that includes metacharacters or source code, then the code will be executed by the web browser as it displays the HTTP response.
func someHandler(w http.ResponseWriter, r *http.Request){
...
row := db.QueryRow("SELECT name FROM users WHERE id =" + userid)
err := row.Scan(&name)
...
fmt.Fprintln(w, "Username is: ", name)
}
Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker can execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack affects multiple users. XSS began in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker can perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.eid, from an HTTP request and displays it to the user.
<% String eid = request.getParameter("eid"); %>
...
Employee ID: <%= eid %>
eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.
<%...
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("select * from emp where id="+eid);
if (rs != null) {
rs.next();
String name = rs.getString("name");
}
%>
Employee Name: <%= name %>
Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.
...
WebView webview = (WebView) findViewById(R.id.webview);
webview.getSettings().setJavaScriptEnabled(true);
String url = this.getIntent().getExtras().getString("url");
webview.loadUrl(url);
...
url starts with javascript:, JavaScript code that follows executes within the context of the web page inside WebView.Example 1, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.Example 3, a source outside the application stores dangerous data in a database or other data store, and the dangerous data is subsequently read back into the application as trusted data and included in dynamic content.eid, from an HTTP request and displays it to the user.
var http = require('http');
var url = require('url');
...
function listener(request, response){
var eid = url.parse(request.url, true)['query']['eid'];
if (eid !== undefined){
response.write('<p>Welcome, ' + eid + '!</p>');
}
...
}
...
http.createServer(listener).listen(8080);
eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.
var http = require('http');
...
function listener(request, response){
connection.query('SELECT * FROM emp WHERE eid="' + eid + '"', function(err, rows){
if (!err && rows.length > 0){
response.write('<p>Welcome, ' + rows[0].name + '!</p>');
}
...
});
...
}
...
http.createServer(listener).listen(8080);
Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.eid, from an HTTP servlet request, then displays the value back to the user in the servlet's response.
val eid: String = request.getParameter("eid")
...
val out: ServletOutputStream = response.getOutputStream()
out.print("Employee ID: $eid")
...
out.close()
...
eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.
val stmt: Statement = conn.createStatement()
val rs: ResultSet = stmt.executeQuery("select * from emp where id=$eid")
rs.next()
val name: String = rs.getString("name")
...
val out: ServletOutputStream = response.getOutputStream()
out.print("Employee Name: $name")
...
out.close()
...
Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.
...
val webview = findViewById<View>(R.id.webview) as WebView
webview.settings.javaScriptEnabled = true
val url = this.intent.extras!!.getString("url")
webview.loadUrl(url)
...
url starts with javascript:, JavaScript code that follows executes within the context of the web page inside WebView.Example 1, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.Example 3, a source outside the application stores dangerous data in a database or other data store, and the dangerous data is subsequently read back into the application as trusted data and included in dynamic content.myapp://input_to_the_application). The untrusted data in the URL is then used to render HTML output in a UIWebView component.
- (BOOL)application:(UIApplication *)application handleOpenURL:(NSURL *)url {
UIWebView *webView;
NSString *partAfterSlashSlash = [[url host] stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
webView = [[UIWebView alloc] initWithFrame:CGRectMake(0.0,0.0,360.0, 480.0)];
[webView loadHTMLString:partAfterSlashSlash baseURL:nil]
...
Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1, data is read directly from a custom URL scheme and reflected back in the content of a UIWebView response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable iOS application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a custom scheme URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable app. After the app reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.eid, from an HTTP request and displays it to the user.
<?php
$eid = $_GET['eid'];
...
?>
...
<?php
echo "Employee ID: $eid";
?>
eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.
<?php...
$con = mysql_connect($server,$user,$password);
...
$result = mysql_query("select * from emp where id="+eid);
$row = mysql_fetch_array($result)
echo 'Employee name: ', mysql_result($row,0,'name');
...
?>
Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.eid, from an HTTP request and displays it to the user.
...
-- Assume QUERY_STRING looks like EID=EmployeeID
eid := SUBSTR(OWA_UTIL.get_cgi_env('QUERY_STRING'), 5);
HTP.htmlOpen;
HTP.headOpen;
HTP.title ('Employee Information');
HTP.headClose;
HTP.bodyOpen;
HTP.br;
HTP.print('< b >Employee ID: ' || eid || '</ b >');
HTP.br;
HTP.bodyClose;
HTP.htmlClose;
...
eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.
...
SELECT ename INTO name FROM emp WHERE id = eid;
HTP.htmlOpen;
HTP.headOpen;
HTP.title ('Employee Information');
HTP.headClose;
HTP.bodyOpen;
HTP.br;
HTP.print('< b >Employee Name: ' || name || '</ b >');
HTP.br;
HTP.bodyClose;
HTP.htmlClose;
...
Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.eid, from an HTTP request and displays it to the user.
req = self.request() # fetch the request object
eid = req.field('eid',None) # tainted request message
...
self.writeln("Employee ID:" + eid)
eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.
...
cursor.execute("select * from emp where id="+eid)
row = cursor.fetchone()
self.writeln('Employee name: ' + row["emp"]')
...
Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.eid, from an HTTP request and displays it to the user.
eid = req.params['eid'] #gets request parameter 'eid'
Rack::Response.new.finish do |res|
...
res.write("Employee ID: #{eid}")
end
eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.Rack::Request#params() as in Example 1, this sees both GET and POST parameters, so may be vulnerable to various types of attacks other than just having the malicious code appended to the URL.
...
rs = conn.exec_params("select * from emp where id=?", eid)
...
Rack::Response.new.finish do |res|
...
rs.each do |row|
res.write("Employee name: #{escape(row['name'])}")
...
end
end
...
Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.eid, from an HTTP request and displays it to the user.
def getEmployee = Action { implicit request =>
val eid = request.getQueryString("eid")
val employee = getEmployee(eid)
if (employee == Null) {
val html = Html(s"Employee ID ${eid} not found")
Ok(html) as HTML
}
...
}
eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.
...
let webView : WKWebView
let inputTextField : UITextField
webView.loadHTMLString(inputTextField.text, baseURL:nil)
...
inputTextField contains only standard alphanumeric text. If the text within inputTextField includes metacharacters or source code, then the input may be executed as code by the web browser as it displays the HTTP response.myapp://input_to_the_application). The untrusted data in the URL is then used to render HTML output in a UIWebView component.
func application(app: UIApplication, openURL url: NSURL, options: [String : AnyObject]) -> Bool {
...
let name = getQueryStringParameter(url.absoluteString, "name")
let html = "Hi \(name)"
let webView = UIWebView()
webView.loadHTMLString(html, baseURL:nil)
...
}
func getQueryStringParameter(url: String?, param: String) -> String? {
if let url = url, urlComponents = NSURLComponents(string: url), queryItems = (urlComponents.queryItems as? [NSURLQueryItem]) {
return queryItems.filter({ (item) in item.name == param }).first?.value!
}
return nil
}
Example 2, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1, data is read directly from a user-controllable UI component and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, a source outside the target application makes a URL request using the target application's custom URL scheme, and unvalidated data from the URL request subsequently read back into the application as trusted data and included in dynamic content.Example 3, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.eid, from an HTTP request and displays it to the user.
...
eid = Request("eid")
Response.Write "Employee ID:" & eid & "<br/>"
..
eid contains only standard alphanumeric text. If eid has a value that includes metacharacters or source code, then the code is executed by the web browser as it displays the HTTP response.
...
eid = Request("eid")
strSQL = "Select * from emp where id=" & eid
objADORecordSet.Open strSQL, strConnect, adOpenDynamic, adLockOptimistic, adCmdText
while not objRec.EOF
Response.Write "Employee Name:" & objADORecordSet("name")
objADORecordSet.MoveNext
Wend
...
Example 1, this code functions correctly when the values of name are well-behaved, but it does nothing to prevent exploits if they are not. Again, this code can appear less dangerous because the value of name is read from a database, whose contents are apparently managed by the application. However, if the value of name originates from user-supplied data, then the database can be a conduit for malicious content. Without proper input validation on all data stored in the database, an attacker may execute malicious commands in the user's web browser. This type of exploit, known as Persistent (or Stored) XSS, is particularly insidious because the indirection caused by the data store makes it difficult to identify the threat and increases the possibility that the attack might affect multiple users. XSS got its start in this form with web sites that offered a "guestbook" to visitors. Attackers would include JavaScript in their guestbook entries, and all subsequent visitors to the guestbook page would execute the malicious code.Example 1, data is read directly from the HTTP request and reflected back in the HTTP response. Reflected XSS exploits occur when an attacker causes a user to supply dangerous content to a vulnerable web application, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or emailed directly to victims. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces victims to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the user, the content is executed and proceeds to transfer private information, such as cookies that might include session information, from the user's machine to the attacker or perform other nefarious activities.Example 2, the application stores dangerous data in a database or other trusted data store. The dangerous data is subsequently read back into the application and included in dynamic content. Persistent XSS exploits occur when an attacker injects dangerous content into a data store that is later read and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user.
(e+)+
([a-zA-Z]+)*
(e|ee)+
(e+)+
([a-zA-Z]+)*
(e|ee)+
(e+)+
([a-zA-Z]+)*
(e|ee)+
(e+)+
([a-zA-Z]+)*
(e|ee)+
(e+)+
([a-zA-Z]+)*
(e|ee)+
(e+)+
([a-zA-Z]+)*
(e|ee)+
(e+)+
([a-zA-Z]+)*
(e|ee)+
NSString *regex = @"^(e+)+$";
NSPredicate *pred = [NSPRedicate predicateWithFormat:@"SELF MATCHES %@", regex];
if ([pred evaluateWithObject:mystring]) {
//do something
}
(e+)+
([a-zA-Z]+)*
(e|ee)+
(e+)+
([a-zA-Z]+)*
(e|ee)+
(e+)+
([a-zA-Z]+)*
(e+)+
([a-zA-Z]+)*
(e|ee)+
(e+)+
([a-zA-Z]+)*
(e|ee)+
let regex : String = "^(e+)+$"
let pred : NSPredicate = NSPRedicate(format:"SELF MATCHES \(regex)")
if (pred.evaluateWithObject(mystring)) {
//do something
}
Example 1, if the attacker supplies the match string "eeeeZ" then there are 16 internal evaluations that the regex parser must go through to identify a match. If the attacker provides 16 "e"s ("eeeeeeeeeeeeeeeeZ") as the match string then the regex parser must go through 65536 (2^16) evaluations. The attacker may easily consume computing resources by increasing the number of consecutive match characters. There are no known regular expression implementations that are immune to this vulnerability. All platforms and languages are vulnerable to this attack.author, from an HTTP request and sets it in a cookie header of an HTTP response.
...
author = request->get_form_field( 'author' ).
response->set_cookie( name = 'author' value = author ).
...
HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...
AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:
HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker
HTTP/1.1 200 OK
...
IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.
@HttpGet
global static void doGet() {
...
Map<String, String> params = ApexPages.currentPage().getParameters();
RestResponse res = RestContext.response;
res.addHeader(params.get('name'), params.get('value'));
...
}
author and Jane Smith, the HTTP response including this header might take the following form:
HTTP/1.1 200 OK
...
author:Jane Smith
...
HTTP/1.1 200 OK\r\n...foo and bar, then the HTTP response would be split into two responses of the following form:
HTTP/1.1 200 OK
...
HTTP/1.1 200 OK
...
foo:bar
HttpResponse.AddHeader() method. If you are using the latest .NET framework that prevents setting headers with new line characters, then your application might not be vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.author, from an HTTP request and sets it in a cookie header of an HTTP response.
protected System.Web.UI.WebControls.TextBox Author;
...
string author = Author.Text;
Cookie cookie = new Cookie("author", author);
...
HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...
Author.Text does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:
HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker
HTTP/1.1 200 OK
...
author, from an HTML form and sets it in a cookie header of an HTTP response.
...
EXEC CICS
WEB READ
FORMFIELD(NAME)
VALUE(AUTHOR)
...
END-EXEC.
EXEC CICS
WEB WRITE
HTTPHEADER(COOKIE)
VALUE(AUTHOR)
...
END-EXEC.
...
HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...
AUTHOR does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:
HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker
HTTP/1.1 200 OK
...
IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.author, from a web form and sets it in a cookie header of an HTTP response.
<cfcookie name = "author"
value = "#Form.author#"
expires = "NOW">
HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...
AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:
HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker
HTTP/1/1 200 OK
...
IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.
final server = await HttpServer.bind('localhost', 18081);
server.listen((request) async {
final headers = request.headers;
final contentType = headers.value('content-type');
final client = HttpClient();
final clientRequest = await client.getUrl(Uri.parse('https://example.com'));
clientRequest.headers.add('Content-Type', contentType as Object);
});
author, from an HTTP request and sets it in a cookie header of an HTTP response.
...
author := request.FormValue("AUTHOR_PARAM")
cookie := http.Cookie{
Name: "author",
Value: author,
Domain: "www.example.com",
}
http.SetCookie(w, &cookie)
...
IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.author, from an HTTP request and sets it in a cookie header of an HTTP response.
String author = request.getParameter(AUTHOR_PARAM);
...
Cookie cookie = new Cookie("author", author);
cookie.setMaxAge(cookieExpiration);
response.addCookie(cookie);
HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...
AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:
HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker
HTTP/1.1 200 OK
...
author, from an HTTP request and sets it in a cookie header of an HTTP response.
author = form.author.value;
...
document.cookie = "author=" + author + ";expires="+cookieExpiration;
...
HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...
AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:
HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker
HTTP/1.1 200 OK
...
IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.name and value may be controlled by an attacker. The code sets an HTTP header whose name and value may be controlled by an attacker:
...
NSURLSessionConfiguration * config = [[NSURLSessionConfiguration alloc] init];
NSMutableDictionary *dict = @{};
[dict setObject:value forKey:name];
[config setHTTPAdditionalHeaders:dict];
...
author and Jane Smith, the HTTP response including this header might take the following form:
HTTP/1.1 200 OK
...
author:Jane Smith
...
HTTP/1.1 200 OK\r\n...foo and bar, then the HTTP response would be split into two responses of the following form:
HTTP/1.1 200 OK
...
HTTP/1.1 200 OK
...
foo:bar
header() function. If your version of PHP prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.
<?php
$location = $_GET['some_location'];
...
header("location: $location");
?>
HTTP/1.1 200 OK
...
location: index.html
...
some_location does not contain any CR and LF characters. If an attacker submits a malicious string, such as "index.html\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:
HTTP/1.1 200 OK
...
location: index.html
HTTP/1.1 200 OK
...
author, from an HTTP request and sets it in a cookie header of an HTTP response.
...
-- Assume QUERY_STRING looks like AUTHOR_PARAM=Name
author := SUBSTR(OWA_UTIL.get_cgi_env('QUERY_STRING'), 14);
OWA_UTIL.mime_header('text/html', false);
OWA_COOKE.send('author', author);
OWA_UTIL.http_header_close;
...
HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...
AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:
HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker
HTTP/1.1 200 OK
...
location = req.field('some_location')
...
response.addHeader("location",location)
HTTP/1.1 200 OK
...
location: index.html
...
some_location does not contain any CR and LF characters. If an attacker submits a malicious string, such as "index.html\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:
HTTP/1.1 200 OK
...
location: index.html
HTTP/1.1 200 OK
...
IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.author, from an HTTP request and uses this in a get request to another part of the site.
author = req.params[AUTHOR_PARAM]
http = Net::HTTP.new(URI("http://www.mysite.com"))
http.post('/index.php', "author=#{author}")
POST /index.php HTTP/1.1
Host: www.mysite.com
author=Jane Smith
...
AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nPOST /index.php HTTP/1.1\r\n...", then the HTTP response would be split into two responses of the following form:
POST /index.php HTTP/1.1
Host: www.mysite.com
author=Wiley Hacker
POST /index.php HTTP/1.1
...
IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.name and value may be controlled by an attacker. The code sets an HTTP header whose name and value may be controlled by an attacker:
...
var headers = []
headers[name] = value
let config = NSURLSessionConfiguration.backgroundSessionConfigurationWithIdentifier("com.acme")
config.HTTPAdditionalHeaders = headers
...
author and Jane Smith, the HTTP response including this header might take the following form:
HTTP/1.1 200 OK
...
author:Jane Smith
...
HTTP/1.1 200 OK\r\n...foo and bar, then the HTTP response would be split into two responses of the following form:
HTTP/1.1 200 OK
...
HTTP/1.1 200 OK
...
foo:bar
author, from an HTTP request and sets it in a cookie header of an HTTP response.
...
author = Request.Form(AUTHOR_PARAM)
Response.Cookies("author") = author
Response.Cookies("author").Expires = cookieExpiration
...
HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...
AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:
HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker
HTTP/1.1 200 OK
...
IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.author, from an HTTP request and sets it in a cookie header of an HTTP response.
...
author = request->get_form_field( 'author' ).
response->set_cookie( name = 'author' value = author ).
...
HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...
AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:
HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker
HTTP/1.1 200 OK
...
IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.author, from an HTTP request and sets it in a cookie header of an HTTP response.
...
Cookie cookie = new Cookie('author', author, '/', -1, false);
ApexPages.currentPage().setCookies(new Cookie[] {cookie});
...
HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...
author does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:
HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker
HTTP/1.1 200 OK
...
IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.author, from an HTTP request and sets it in a cookie header of an HTTP response.
protected System.Web.UI.WebControls.TextBox Author;
...
string author = Author.Text;
Cookie cookie = new Cookie("author", author);
...
HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...
AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:
HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker
HTTP/1.1 200 OK
...
IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.author, from an HTTP request and sets it in a cookie header of an HTTP response.
<cfcookie name = "author"
value = "#Form.author#"
expires = "NOW">
HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...
AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:
HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker
HTTP/1.1 200 OK
...
IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.author, from an HTTP request and sets it in a cookie header of an HTTP response.
...
author := request.FormValue("AUTHOR_PARAM")
cookie := http.Cookie{
Name: "author",
Value: author,
Domain: "www.example.com",
}
http.SetCookie(w, &cookie)
...
HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...
AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response is split into two responses of the following form:
HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker
HTTP/1.1 200 OK
...
IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.author, from an HTTP request and sets it in a cookie header of an HTTP response.
String author = request.getParameter(AUTHOR_PARAM);
...
Cookie cookie = new Cookie("author", author);
cookie.setMaxAge(cookieExpiration);
response.addCookie(cookie);
HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...
AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:
HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker
HTTP/1.1 200 OK
...
Example 1 to the Android platform.Cross-User Defacement: An attacker will be able to make a single request to a vulnerable server that will cause the server to create two responses, the second of which may be misinterpreted as a response to a different request, possibly one made by another user sharing the same TCP connection with the server. This can be accomplished by convincing the user to submit the malicious request themselves, or remotely in situations where the attacker and the user share a common TCP connection to the server, such as a shared proxy server. In the best case, an attacker may leverage this ability to convince users that the application has been hacked, causing users to lose confidence in the security of the application. In the worst case, an attacker may provide specially crafted content designed to mimic the behavior of the application but redirect private information, such as account numbers and passwords, back to the attacker.
...
CookieManager webCookieManager = CookieManager.getInstance();
String author = this.getIntent().getExtras().getString(AUTHOR_PARAM);
String setCookie = "author=" + author + "; max-age=" + cookieExpiration;
webCookieManager.setCookie(url, setCookie);
...
IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.author, from an HTTP request and sets it in a cookie header of an HTTP response.
author = form.author.value;
...
document.cookie = "author=" + author + ";expires="+cookieExpiration;
...
HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...
AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:
HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker
HTTP/1.1 200 OK
...
IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.author, from an HTTP request and sets it in a cookie header of an HTTP response.
<?php
$author = $_GET['AUTHOR_PARAM'];
...
header("author: $author");
?>
HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...
AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:
HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker
HTTP/1.1 200 OK
...
location = req.field('some_location')
...
response.addHeader("location",location)
HTTP/1.1 200 OK
...
location: index.html
...
some_location does not contain any CR and LF characters. If an attacker submits a malicious string, such as "index.html\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:
HTTP/1.1 200 OK
...
location: index.html
HTTP/1.1 200 OK
...
IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.author, from an HTTP request and sets it in a cookie header of an HTTP response.
...
author = Request.Form(AUTHOR_PARAM)
Response.Cookies("author") = author
Response.Cookies("author").Expires = cookieExpiration
...
HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...
AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:
HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker
HTTP/1.1 200 OK
...
Access-Control-Allow-Origin is defined. With this header, a Web server defines which other domains are allowed to access its domain using cross-origin requests. However, exercise caution when defining the header because an overly permissive CORS policy can enable a malicious application to inappropriately communicate with the victim application, which can lead to spoofing, data theft, relay, and other attacks.
Response.AppendHeader("Access-Control-Allow-Origin", "*");
* as the value of the Access-Control-Allow-Origin header indicates that the application's data is accessible to JavaScript running on any domain.Access-Control-Allow-Origin is defined. With this header, a Web server defines which other domains are allowed to access its domain using cross-origin requests. However, exercise caution when defining the header because an overly permissive CORS policy can enable a malicious application to inappropriately communicate with the victim application, which can lead to spoofing, data theft, relay, and other attacks.
<websocket:handlers allowed-origins="*">
<websocket:mapping path="/myHandler" handler="myHandler" />
</websocket:handlers>
* as the value of the Access-Control-Allow-Origin header indicates that the application's data is accessible to JavaScript running on any domain.Access-Control-Allow-Origin is defined. With this header, a Web server defines which other domains are allowed to access its domain using cross-origin requests. However, exercise caution when defining the header because an overly permissive CORS policy can enable a malicious application to inappropriately communicate with the victim application, which can lead to spoofing, data theft, relay, and other attacks.
<?php
header('Access-Control-Allow-Origin: *');
?>
* as the value of the Access-Control-Allow-Origin header indicates that the application's data is accessible to JavaScript running on any domain.Access-Control-Allow-Origin is defined. With this header, a Web server defines which other domains are allowed to access its domain using cross-origin requests. However, exercise caution when defining the header because an overly permissive CORS policy can enable a malicious application to inappropriately communicate with the victim application, which can lead to spoofing, data theft, relay, and other attacks.
response.addHeader("Access-Control-Allow-Origin", "*")
* as the value of the Access-Control-Allow-Origin header indicates that the application's data is accessible to JavaScript running on any domain.Access-Control-Allow-Origin is defined. With this header, a Web server defines which other domains are allowed to access its domain using cross-origin requests. However, exercise caution when defining the header because an overly permissive CORS policy can enable a malicious application to inappropriately communicate with the victim application, which can lead to spoofing, data theft, relay, and other attacks.
play.filters.cors {
pathPrefixes = ["/some/path", ...]
allowedOrigins = ["*"]
allowedHttpMethods = ["GET", "POST"]
allowedHttpHeaders = ["Accept"]
preflightMaxAge = 3 days
}
* as the value of the Access-Control-Allow-Origin header indicates that the application's data is accessible to JavaScript running on any domain.Access-Control-Allow-Origin is defined. With this header, a Web server defines which other domains are allowed to access its domain using cross-origin requests. However, exercise caution when defining the header because an overly permissive CORS policy can enable a malicious application to inappropriately communicate with the victim application, which can lead to spoofing, data theft, relay, and other attacks.
Response.AddHeader "Access-Control-Allow-Origin", "*"
* as the value of the Access-Control-Allow-Origin header indicates that the application's data is accessible to JavaScript running on any domain.
FORM GenerateReceiptURL CHANGING baseUrl TYPE string.
DATA: r TYPE REF TO cl_abap_random,
var1 TYPE i,
var2 TYPE i,
var3 TYPE n.
GET TIME.
var1 = sy-uzeit.
r = cl_abap_random=>create( seed = var1 ).
r->int31( RECEIVING value = var2 ).
var3 = var2.
CONCATENATE baseUrl var3 ".html" INTO baseUrl.
ENDFORM.
CL_ABAP_RANDOM->INT31 function to generate "unique" identifiers for the receipt pages it generates. Since CL_ABAP_RANDOM is a statistical PRNG, it is easy for an attacker to guess the strings it generates. Although the underlying design of the receipt system is also faulty, it would be more secure if it used a random number generator that did not produce predictable receipt identifiers, such as a cryptographic PRNG.
string GenerateReceiptURL(string baseUrl) {
Random Gen = new Random();
return (baseUrl + Gen.Next().toString() + ".html");
}
Random.Next() function to generate "unique" identifiers for the receipt pages it generates. Since Random.Next() is a statistical PRNG, it is easy for an attacker to guess the strings it generates. Although the underlying design of the receipt system is also faulty, it would be more secure if it used a random number generator that did not produce predictable receipt identifiers, such as a cryptographic PRNG.
char* CreateReceiptURL() {
int num;
time_t t1;
char *URL = (char*) malloc(MAX_URL);
if (URL) {
(void) time(&t1);
srand48((long) t1); /* use time to set seed */
sprintf(URL, "%s%d%s", "http://test.com/", lrand48(), ".html");
}
return URL;
}
lrand48() function to generate "unique" identifiers for the receipt pages it generates. Since lrand48() is a statistical PRNG, it is easy for an attacker to guess the strings it generates. Although the underlying design of the receipt system is also faulty, it would be more secure if it used a random number generator that did not produce predictable receipt identifiers.
<cfoutput>
Receipt: #baseUrl##Rand()#.cfm
</cfoutput>
Rand() function to generate "unique" identifiers for the receipt pages it generates. Since Rand() is a statistical PRNG, it is easy for an attacker to guess the strings it generates. Although the underlying design of the receipt system is also faulty, it would be more secure if it used a random number generator that did not produce predictable receipt identifiers, such as a cryptographic PRNG.
import "math/rand"
...
var mathRand = rand.New(rand.NewSource(1))
rsa.GenerateKey(mathRand, 2048)
rand.New() function to generate randomness for an RSA key. Since rand.New() is a statistical PRNG, it is easy for an attacker to guess the value it generates.
String GenerateReceiptURL(String baseUrl) {
Random ranGen = new Random();
ranGen.setSeed((new Date()).getTime());
return (baseUrl + ranGen.nextInt(400000000) + ".html");
}
Random.nextInt() function to generate "unique" identifiers for the receipt pages it generates. Since Random.nextInt() is a statistical PRNG, it is easy for an attacker to guess the strings it generates. Although the underlying design of the receipt system is also faulty, it would be more secure if it used a random number generator that did not produce predictable receipt identifiers, such as a cryptographic PRNG.
function genReceiptURL (baseURL){
var randNum = Math.random();
var receiptURL = baseURL + randNum + ".html";
return receiptURL;
}
Math.random() function to generate "unique" identifiers for the receipt pages it generates. Since Math.random() is a statistical PRNG, it is easy for an attacker to guess the strings it generates. Although the underlying design of the receipt system is also faulty, it would be more secure if it used a random number generator that did not produce predictable receipt identifiers, such as a cryptographic PRNG.
fun GenerateReceiptURL(baseUrl: String): String {
val ranGen = Random(Date().getTime())
return baseUrl + ranGen.nextInt(400000000).toString() + ".html"
}
Random.nextInt() function to generate "unique" identifiers for the receipt pages it generates. Since Random.nextInt() is a statistical PRNG, it is easy for an attacker to guess the strings it generates. Although the underlying design of the receipt system is also faulty, it would be more secure if it used a random number generator that did not produce predictable receipt identifiers, such as a cryptographic PRNG.
function genReceiptURL($baseURL) {
$randNum = rand();
$receiptURL = $baseURL . $randNum . ".html";
return $receiptURL;
}
rand() function to generate "unique" identifiers for the receipt pages it generates. Since rand() is a statistical PRNG, it is easy for an attacker to guess the strings it generates. Although the underlying design of the receipt system is also faulty, it would be more secure if it used a random number generator that did not produce predictable receipt identifiers, such as a cryptographic PRNG.
CREATE or REPLACE FUNCTION CREATE_RECEIPT_URL
RETURN VARCHAR2
AS
rnum VARCHAR2(48);
time TIMESTAMP;
url VARCHAR2(MAX_URL)
BEGIN
time := SYSTIMESTAMP;
DBMS_RANDOM.SEED(time);
rnum := DBMS_RANDOM.STRING('x', 48);
url := 'http://test.com/' || rnum || '.html';
RETURN url;
END
DBMS_RANDOM.SEED() function to generate "unique" identifiers for the receipt pages it generates. Since DBMS_RANDOM.SEED() is a statistical PRNG, it is easy for an attacker to guess the strings it generates. Although the underlying design of the receipt system is also faulty, it would be more secure if it used a random number generator that did not produce predictable receipt identifiers.
def genReceiptURL(self,baseURL):
randNum = random.random()
receiptURL = baseURL + randNum + ".html"
return receiptURL
rand() function to generate "unique" identifiers for the receipt pages it generates. Since rand() is a statistical PRNG, it is easy for an attacker to guess the strings it generates. Although the underlying design of the receipt system is also faulty, it would be more secure if it used a random number generator that did not produce predictable receipt identifiers, such as a cryptographic PRNG.
def generateReceiptURL(baseUrl) {
randNum = rand(400000000)
return ("#{baseUrl}#{randNum}.html");
}
Kernel.rand() function to generate "unique" identifiers for the receipt pages it generates. Since Kernel.rand() is a statistical PRNG, it is easy for an attacker to guess the strings it generates.
def GenerateReceiptURL(baseUrl : String) : String {
val ranGen = new scala.util.Random()
ranGen.setSeed((new Date()).getTime())
return (baseUrl + ranGen.nextInt(400000000) + ".html")
}
Random.nextInt() function to generate "unique" identifiers for the receipt pages it generates. Since Random.nextInt() is a statistical PRNG, it is easy for an attacker to guess the strings it generates. Although the underlying design of the receipt system is also faulty, it would be more secure if it used a random number generator that did not produce predictable receipt identifiers, such as a cryptographic PRNG.
sqlite3_randomness(10, &reset_token)
...
Function genReceiptURL(baseURL)
dim randNum
randNum = Rnd()
genReceiptURL = baseURL & randNum & ".html"
End Function
...
Rnd() function to generate "unique" identifiers for the receipt pages it generates. Since Rnd() is a statistical PRNG, it is easy for an attacker to guess the strings it generates. Although the underlying design of the receipt system is also faulty, it would be more secure if it used a random number generator that did not produce predictable receipt identifiers, such as a cryptographic PRNG.CL_ABAP_RANDOM class or its variants) is seeded with a specific constant value, the values returned by GET_NEXT, INT and similar methods which return or assign values are predictable for an attacker that can collect a number of PRNG outputs.random_gen2 are predictable from the object random_gen1.
DATA: random_gen1 TYPE REF TO cl_abap_random,
random_gen2 TYPE REF TO cl_abap_random,
var1 TYPE i,
var2 TYPE i.
random_gen1 = cl_abap_random=>create( seed = '1234' ).
DO 10 TIMES.
CALL METHOD random_gen1->int
RECEIVING
value = var1.
WRITE:/ var1.
ENDDO.
random_gen2 = cl_abap_random=>create( seed = '1234' ).
DO 10 TIMES.
CALL METHOD random_gen2->int
RECEIVING
value = var2.
WRITE:/ var2.
ENDDO.
random_gen1 and random_gen2 were identically seeded, so var1 = var2rand()) is seeded with a specific value (using a function like srand(unsigned int)), the values returned by rand() and similar methods which return or assign values are predictable for an attacker that can collect a number of PRNG outputs.
srand(2223333);
float randomNum = (rand() % 100);
syslog(LOG_INFO, "Random: %1.2f", randomNum);
randomNum = (rand() % 100);
syslog(LOG_INFO, "Random: %1.2f", randomNum);
srand(2223333);
float randomNum2 = (rand() % 100);
syslog(LOG_INFO, "Random: %1.2f", randomNum2);
randomNum2 = (rand() % 100);
syslog(LOG_INFO, "Random: %1.2f", randomNum2);
srand(1231234);
float randomNum3 = (rand() % 100);
syslog(LOG_INFO, "Random: %1.2f", randomNum3);
randomNum3 = (rand() % 100);
syslog(LOG_INFO, "Random: %1.2f", randomNum3);
randomNum1 and randomNum2 were identically seeded, so each call to rand() after the call which seeds the pseudorandom number generator srand(2223333), will result in the same outputs in the same calling order. For example, the output might resemble the following:
Random: 32.00
Random: 73.00
Random: 32.00
Random: 73.00
Random: 15.00
Random: 75.00
math.Rand.New(Source)), the values returned by math.Rand.Int() and similar methods which return or assign values are predictable for an attacker that can collect a number of PRNG outputs.
randomGen := rand.New(rand.NewSource(12345))
randomInt1 := randomGen.nextInt()
randomGen.Seed(12345)
randomInt2 := randomGen.nextInt()
nextInt() after the call that seeded the pseudorandom number generator (randomGen.Seed(12345)), results in the same outputs and in the same order.Random) is seeded with a specific value (using a function such as Random.setSeed()), the values returned by Random.nextInt() and similar methods which return or assign values are predictable for an attacker that can collect a number of PRNG outputs.Random object randomGen2 are predictable from the Random object randomGen1.
Random randomGen1 = new Random();
randomGen1.setSeed(12345);
int randomInt1 = randomGen1.nextInt();
byte[] bytes1 = new byte[4];
randomGen1.nextBytes(bytes1);
Random randomGen2 = new Random();
randomGen2.setSeed(12345);
int randomInt2 = randomGen2.nextInt();
byte[] bytes2 = new byte[4];
randomGen2.nextBytes(bytes2);
randomGen1 and randomGen2 were identically seeded, so randomInt1 == randomInt2, and corresponding values of arrays bytes1[] and bytes2[] are equal.Random) is seeded with a specific value (using function such as Random(Int)), the values returned by Random.nextInt() and similar methods which return or assign values are predictable for an attacker that can collect a number of PRNG outputs.Random object randomGen2 are predictable from the Random object randomGen1.
val randomGen1 = Random(12345)
val randomInt1 = randomGen1.nextInt()
val byteArray1 = ByteArray(4)
randomGen1.nextBytes(byteArray1)
val randomGen2 = Random(12345)
val randomInt2 = randomGen2.nextInt()
val byteArray2 = ByteArray(4)
randomGen2.nextBytes(byteArray2)
randomGen1 and randomGen2 were identically seeded, so randomInt1 == randomInt2, and corresponding values of arrays byteArray1 and byteArray2 are equal.
...
import random
random.seed(123456)
print "Random: %d" % random.randint(1,100)
print "Random: %d" % random.randint(1,100)
print "Random: %d" % random.randint(1,100)
random.seed(123456)
print "Random: %d" % random.randint(1,100)
print "Random: %d" % random.randint(1,100)
print "Random: %d" % random.randint(1,100)
...
randint() after the call that seeded the pseudorandom number generator (random.seed(123456)), will result in the same outputs in the same output in the same order. For example, the output might resemble the following:
Random: 81
Random: 80
Random: 3
Random: 81
Random: 80
Random: 3
Random) is seeded with a specific value (using a function like Random.setSeed()), the values returned by Random.nextInt() and similar methods which return or assign values are predictable for an attacker that can collect a number of PRNG outputs.Random object randomGen2 are predictable from the Random object randomGen1.
val randomGen1 = new Random()
randomGen1.setSeed(12345)
val randomInt1 = randomGen1.nextInt()
val bytes1 = new byte[4]
randomGen1.nextBytes(bytes1)
val randomGen2 = new Random()
randomGen2.setSeed(12345)
val randomInt2 = randomGen2.nextInt()
val bytes2 = new byte[4]
randomGen2.nextBytes(bytes2)
randomGen1 and randomGen2 were identically seeded, so randomInt1 == randomInt2, and corresponding values of arrays bytes1[] and bytes2[] are equal.CL_ABAP_RANDOM (or its variants) should not be initialized with a tainted argument. Doing so allows an attacker to control the value used to seed the pseudorandom number generator, and therefore predict the sequence of values produced by calls to methods including but not limited to: GET_NEXT, INT, FLOAT, PACKED.rand()), which are passed a seed (such as srand()); should not be called with a tainted argument. Doing so allows an attacker to control the value used to seed the pseudorandom number generator, and therefore predict the sequence of values (usually integers) produced by calls to the pseudorandom number generator.ed25519.NewKeyFromSeed(), should not be called with a tainted argument. Doing so allows an attacker to control the value used to seed the pseudorandom number generator, and then can predict the sequence of values produced by calls to the pseudorandom number generator.Random.setSeed() should not be called with a tainted integer argument. Doing so allows an attacker to control the value used to seed the pseudorandom number generator, and therefore predict the sequence of values (usually integers) produced by calls to Random.nextInt(), Random.nextShort(), Random.nextLong(), or returned by Random.nextBoolean(), or set in Random.nextBytes(byte[]).Random.setSeed() should not be called with a tainted integer argument. Doing so allows an attacker to control the value used to seed the pseudorandom number generator, and therefore predict the sequence of values (usually integers) produced by calls to Random.nextInt(), Random.nextLong(), Random.nextDouble(), or returned by Random.nextBoolean(), or set in Random.nextBytes(ByteArray).random.randint()); should not be called with a tainted argument. Doing so allows an attacker to control the value used to seed the pseudorandom number generator, and hence be able to predict the sequence of values (usually integers) produced by calls to the pseudorandom number generator.Random.setSeed() should not be called with a tainted integer argument. Doing so allows an attacker to control the value used to seed the pseudorandom number generator, and therefore predict the sequence of values (usually integers) produced by calls to Random.nextInt(), Random.nextShort(), Random.nextLong(), or returned by Random.nextBoolean(), or set in Random.nextBytes(byte[]).