if (password eq '783-1') {
getURL('http://.../client_pages/.../783.html', '');
}
else {
if (password eq '771-2 Update') {
getURL('http://.../client_pages/.../771.html', '');
}
else {
if (password eq '7990') {
getURL('http://.../client_pages/.../799.html', '');
}
}
ExternalInterface
, fscommand
or getURL
. XML.load
, loadVariables
, LoadVars.load
etc. If a Flash application should not communicate with the browser or needs to make any networking calls, the AllowNetworkingAccess
tag must be set to "none".AllowNetworkingAccess
tag must be set to "none"
. AllowNetworkingAccess
tag should be set to "internal"
. AllowNetworkingAccess
tag must be set to "all"
. ENABLEDEBUGGER
and ENABLEDEBUGGER2
enables support for remote debugging and also contains a poorly salted MD5 password hash. The tag does not offer any security guarantees and can be easily circumvented by using any hex editor tool. Not only is the remote debugging protection easily bypassed, the password the developer used to secure the file is easily recoverable. Flash uses a 16-bit salt added to the password and applies the MD5 hash algorithm to it. This is a weak salt and the password can be recovered using password cracking programs.crossdomain.xml
configuration file. However, caution should be taken when changing the settings because an overly permissive cross-domain policy will allow a malicious application to communicate with the victim application in an inappropriate way, leading to spoofing, data theft, relay, and other attacks.
flash.system.Security.allowDomain("*");
*
as the argument to allowDomain()
indicates that the application's data is accessible to other SWF applications from any domain.crossdomain.xml
configuration file. Starting with Flash Player 9,0,124,0, Adobe also introduced the capability to define which custom headers Flash Player can send across domains. However, caution should be taken when defining these settings because an overly permissive custom headers policy, when applied together with the overly permissive cross-domain policy, will allow a malicious application to send headers of their choosing to the target application, potentially leading to a variety of attacks or causing errors in the execution of the application that does not know how to handle received headers.
<cross-domain-policy>
<allow-http-request-headers-from domain="*" headers="*"/>
</cross-domain-policy>
*
as the value of the headers
attribute indicates that any header will be sent across domains.crossdomain.xml
configuration file. However, caution should be taken when deciding who can influence the settings because an overly permissive cross-domain policy will allow a malicious application to communicate with the victim application in an inappropriate way, leading to spoofing, data theft, relay, and other attacks. Policy restrictions bypass vulnerabilities occur when:Example 2: The following code uses the value of one of the parameters to the loaded SWF file to define the list of trusted domains.
...
var params:Object = LoaderInfo(this.root.loaderInfo).parameters;
var url:String = String(params["url"]);
flash.system.Security.loadPolicyFile(url);
...
...
var params:Object = LoaderInfo(this.root.loaderInfo).parameters;
var domain:String = String(params["domain"]);
flash.system.Security.allowDomain(domain);
...
crossdomain.xml
configuration file. However, caution should be taken when defining these settings because HTTP loaded SWF applications are subject to man-in-the-middle attacks, and thus should not be trusted.allowInsecureDomain()
, which turns off the restriction that prevents HTTP loaded SWF applications from accessing the data of HTTPS loaded SWF applications.
flash.system.Security.allowInsecureDomain("*");
services-config.xml
descriptor file specifies a "Logging" XML element to describe various aspects of logging. It looks like the following:
<logging>
<target class="flex.messaging.log.ConsoleTarget" level="Debug">
<properties>
<prefix>[BlazeDS]</prefix>
<includeDate>false</includeDate>
<includeTime>false</includeTime>
<includeLevel>false</includeLevel>
<includeCategory>false</includeCategory>
</properties>
<filters>
<pattern>Endpoint.*</pattern>
<pattern>Service.*</pattern>
<pattern>Configuration</pattern>
</filters>
</target>
</logging>
target
tag takes an optional attribute called level
, which indicates the log level. If the debug level is set to too detailed a level, your application may write sensitive data to the log file.sprintf()
, FormatMessageW()
, or syslog()
.snprintf()
.
int main(int argc, char **argv){
char buf[128];
...
snprintf(buf,128,argv[1]);
}
%x
, than the function takes as arguments to be formatted. (In this example, the function takes no arguments to be formatted.) By using the %n
formatting directive, the attacker may write to the stack, causing snprintf()
to write the number of bytes output thus far to the specified argument (rather than reading a value from the argument, which is the intended behavior). A sophisticated version of this attack will use four staggered writes to completely control the value of a pointer on the stack.
printf("%d %d %1$d %1$d\n", 5, 9);
5 9 5 5
Example 1
.syslog()
function is sometimes used as follows:
...
syslog(LOG_ERR, cmdBuf);
...
syslog()
is a format string, any formatting directives included in cmdBuf
are interpreted as described in Example 1
.syslog()
:
...
syslog(LOG_ERR, "%s", cmdBuf);
...
sprintf()
, FormatMessageW()
, syslog()
, NSLog
, or NSString.stringWithFormat
Example 1: The following code utilizes a command line argument as a format string in NSString.stringWithFormat:
.
int main(int argc, char **argv){
char buf[128];
...
[NSString stringWithFormat:argv[1], argv[2] ];
}
%x
, than the function takes as arguments to be formatted. (In this example, the function takes no arguments to be formatted.)
printf("%d %d %1$d %1$d\n", 5, 9);
5 9 5 5
Example 1
.syslog()
function is sometimes used as follows:
...
syslog(LOG_ERR, cmdBuf);
...
syslog()
is a format string, any formatting directives included in cmdBuf
are interpreted as described in Example 1
.syslog()
:Example 4: Apple core classes provide interesting avenues for exploiting format string vulnerabilities.
...
syslog(LOG_ERR, "%s", cmdBuf);
...
String.stringByAppendingFormat()
function is sometimes used as follows:
...
NSString test = @"Sample Text.";
test = [test stringByAppendingFormat:[MyClass
formatInput:inputControl.text]];
...
stringByAppendingFormat()
:
...
NSString test = @"Sample Text.";
test = [test stringByAppendingFormat:@"%@", [MyClass
formatInput:inputControl.text]];
...
strncpy()
, can cause vulnerabilities when used incorrectly. The combination of memory manipulation and mistaken assumptions about the size or makeup of a piece of data is the root cause of most buffer overflows.
void wrongNumberArgs(char *s, float f, int d) {
char buf[1024];
sprintf(buf, "Wrong number of %.512s");
}
strncpy()
, can cause vulnerabilities when used incorrectly. The combination of memory manipulation and mistaken assumptions about the size or makeup of a piece of data is the root cause of most buffer overflows.f
from a float using a %d
format specifier.
void ArgTypeMismatch(float f, int d, char *s, wchar *ws) {
char buf[1024];
sprintf(buf, "Wrong type of %d", f);
...
}
...
String lang = Request.Form["lang"];
WebClient client = new WebClient();
client.BaseAddress = url;
NameValueCollection myQueryStringCollection = new NameValueCollection();
myQueryStringCollection.Add("q", lang);
client.QueryString = myQueryStringCollection;
Stream data = client.OpenRead(url);
...
lang
such as en&poll_id=1
, and then the attacker may be able to change the poll_id
at will.
...
String lang = request.getParameter("lang");
GetMethod get = new GetMethod("http://www.example.com");
get.setQueryString("lang=" + lang + "&poll_id=" + poll_id);
get.execute();
...
lang
such as en&poll_id=1
, and then the attacker will be able to change the poll_id
at will.
<%
...
$id = $_GET["id"];
header("Location: http://www.host.com/election.php?poll_id=" . $id);
...
%>
name=alice
specified, but they've added an additional name=alice&
, and if this is being used on a server that takes the first occurrence, then this may impersonate alice
in order to get further information regarding her account.returningObjectFlag
to true
on the javax.naming.directory.SearchControls
instance passed to the search
method or by using a library function that sets this flag on its behalf.
<beans ... >
<authentication-manager>
<ldap-authentication-provider
user-search-filter="(uid={0})"
user-search-base="ou=users,dc=example,dc=org"
group-search-filter="(uniqueMember={0})"
group-search-base="ou=groups,dc=example,dc=org"
group-role-attribute="cn"
role-prefix="ROLE_">
</ldap-authentication-provider>
</authentication-manager>
</beans>
chroot()
should be dropped immediately after the operation is performed.chroot()
, it must first acquire root
privilege. As soon as the privileged operation has completed, the program should drop root
privilege and return to the privilege level of the invoking user.chroot()
to restrict the application to a subset of the file system below APP_HOME
in order to prevent an attacker from using the program to gain unauthorized access to files located elsewhere. The code then opens a file specified by the user and processes the contents of the file.
...
chroot(APP_HOME);
chdir("/");
FILE* data = fopen(argv[1], "r+");
...
setuid()
with some non-zero value means the application is continuing to operate with unnecessary root
privileges. Any successful exploit carried out by an attacker against the application can now result in a privilege escalation attack because any malicious operations will be performed with the privileges of the superuser. If the application drops to the privilege level of a non-root
user, the potential for damage is substantially reduced.
...
DATA log_msg TYPE bal_s_msg.
val = request->get_form_field( 'val' ).
log_msg-msgid = 'XY'.
log_msg-msgty = 'E'.
log_msg-msgno = '123'.
log_msg-msgv1 = 'VAL: '.
log_msg-msgv2 = val.
CALL FUNCTION 'BAL_LOG_MSG_ADD'
EXPORTING
I_S_MSG = log_msg
EXCEPTIONS
LOG_NOT_FOUND = 1
MSG_INCONSISTENT = 2
LOG_IS_FULL = 3
OTHERS = 4.
...
FOO
" for val
, the following entry is logged:
XY E 123 VAL: FOO
FOO XY E 124 VAL: BAR
", the following entry is logged:
XY E 123 VAL: FOO XY E 124 VAL: BAR
var params:Object = LoaderInfo(this.root.loaderInfo).parameters;
var val:String = String(params["username"]);
var value:Number = parseInt(val);
if (value == Number.NaN) {
trace("Failed to parse val = " + val);
}
twenty-one
" for val
, the following entry is logged:
Failed to parse val=twenty-one
twenty-one%0a%0aINFO:+User+logged+out%3dbadguy
", the following entry is logged:
Failed to parse val=twenty-one
User logged out=badguy
...
string val = (string)Session["val"];
try {
int value = Int32.Parse(val);
}
catch (FormatException fe) {
log.Info("Failed to parse val= " + val);
}
...
twenty-one
" for val
, the following entry is logged:
INFO: Failed to parse val=twenty-one
twenty-one%0a%0aINFO:+User+logged+out%3dbadguy
", the following entry is logged:
INFO: Failed to parse val=twenty-one
INFO: User logged out=badguy
long value = strtol(val, &endPtr, 10);
if (*endPtr != '\0')
syslog(LOG_INFO,"Illegal value = %s",val);
...
twenty-one
" for val
, the following entry is logged:
Illegal value=twenty-one
twenty-one\n\nINFO: User logged out=evil
", the following entry is logged:
INFO: Illegal value=twenty-one
INFO: User logged out=evil
...
01 LOGAREA.
05 VALHEADER PIC X(50) VALUE 'VAL: '.
05 VAL PIC X(50).
...
EXEC CICS
WEB READ
FORMFIELD(NAME)
VALUE(VAL)
...
END-EXEC.
EXEC DLI
LOG
FROM(LOGAREA)
LENGTH(50)
END-EXEC.
...
FOO
" for VAL
, the following entry is logged:
VAL: FOO
FOO VAL: BAR
", the following entry is logged:
VAL: FOO VAL: BAR
<cflog file="app_log" application="No" Thread="No"
text="Failed to parse val="#Form.val#">
twenty-one
" for val
, the following entry is logged:
"Information",,"02/28/01","14:50:37",,"Failed to parse val=twenty-one"
twenty-one%0a%0a%22Information%22%2C%2C%2202/28/01%22%2C%2214:53:40%22%2C%2C%22User%20logged%20out:%20badguy%22
", the following entry is logged:
"Information",,"02/28/01","14:50:37",,"Failed to parse val=twenty-one"
"Information",,"02/28/01","14:53:40",,"User logged out: badguy"
func someHandler(w http.ResponseWriter, r *http.Request){
r.parseForm()
name := r.FormValue("name")
logout := r.FormValue("logout")
...
if (logout){
...
} else {
log.Printf("Attempt to log out: name: %s logout: %s", name, logout)
}
}
twenty-one
" for logout
and he was able to create a user with name "admin
", the following entry is logged:
Attempt to log out: name: admin logout: twenty-one
admin+logout:+1+++++++++++++++++++++++
", the following entry is logged:
Attempt to log out: name: admin logout: 1 logout: twenty-one
...
String val = request.getParameter("val");
try {
int value = Integer.parseInt(val);
}
catch (NumberFormatException nfe) {
log.info("Failed to parse val = " + val);
}
...
twenty-one
" for val
, the following entry is logged:
INFO: Failed to parse val=twenty-one
twenty-one%0a%0aINFO:+User+logged+out%3dbadguy
", the following entry is logged:
INFO: Failed to parse val=twenty-one
INFO: User logged out=badguy
Example 1
to the Android platform.
...
String val = this.getIntent().getExtras().getString("val");
try {
int value = Integer.parseInt();
}
catch (NumberFormatException nfe) {
Log.e(TAG, "Failed to parse val = " + val);
}
...
var cp = require('child_process');
var http = require('http');
var url = require('url');
function listener(request, response){
var val = url.parse(request.url, true)['query']['val'];
if (isNaN(val)){
console.log("INFO: Failed to parse val = " + val);
}
...
}
...
http.createServer(listener).listen(8080);
...
twenty-one
" for val
, the following entry is logged:
INFO: Failed to parse val = twenty-one
twenty-one%0a%0aINFO:+User+logged+out%3dbadguy
", the following entry is logged:
INFO: Failed to parse val=twenty-one
INFO: User logged out=badguy
long value = strtol(val, &endPtr, 10);
if (*endPtr != '\0')
NSLog("Illegal value = %s",val);
...
twenty-one
" for val
, the following entry is logged:
INFO: Illegal value=twenty-one
twenty-one\n\nINFO: User logged out=evil
", the following entry is logged:
INFO: Illegal value=twenty-one
INFO: User logged out=evil
<?php
$name =$_GET['name'];
...
$logout =$_GET['logout'];
if(is_numeric($logout))
{
...
}
else
{
trigger_error("Attempt to log out: name: $name logout: $val");
}
?>
twenty-one
" for logout
and he was able to create a user with name "admin
", the following entry is logged:
PHP Notice: Attempt to log out: name: admin logout: twenty-one
admin+logout:+1+++++++++++++++++++++++
", the following entry is logged:
PHP Notice: Attempt to log out: name: admin logout: 1 logout: twenty-one
name = req.field('name')
...
logout = req.field('logout')
if (logout):
...
else:
logger.error("Attempt to log out: name: %s logout: %s" % (name,logout))
twenty-one
" for logout
and he was able to create a user with name "admin
", the following entry is logged:
Attempt to log out: name: admin logout: twenty-one
admin+logout:+1+++++++++++++++++++++++
", the following entry is logged:
Attempt to log out: name: admin logout: 1 logout: twenty-one
...
val = req['val']
unless val.respond_to?(:to_int)
logger.info("Failed to parse val")
logger.info(val)
end
...
twenty-one
" for val
, the following entry is logged:
INFO: Failed to parse val
INFO: twenty-one
twenty-one%0a%0aINFO:+User+logged+out%3dbadguy
", the following entry is logged:
INFO: Failed to parse val
INFO: twenty-one
INFO: User logged out=badguy
...
let num = Int(param)
if num == nil {
NSLog("Illegal value = %@", param)
}
...
twenty-one
" for val
, the following entry is logged:
INFO: Illegal value = twenty-one
twenty-one\n\nINFO: User logged out=evil
", the following entry is logged:
INFO: Illegal value=twenty-one
INFO: User logged out=evil
...
Dim Val As Variant
Dim Value As Integer
Set Val = Request.Form("val")
If IsNumeric(Val) Then
Set Value = Val
Else
App.EventLog "Failed to parse val=" & Val, 1
End If
...
twenty-one
" for val
, the following entry is logged:
Failed to parse val=twenty-one
twenty-one%0a%0a+User+logged+out%3dbadguy
", the following entry is logged:
Failed to parse val=twenty-one
User logged out=badguy
CREATE
command that is sent to the IMAP server. An attacker may use this parameter to modify the command sent to the server and inject new commands using CRLF characters.
...
final String foldername = request.getParameter("folder");
IMAPFolder folder = (IMAPFolder) store.getFolder("INBOX");
...
folder.doCommand(new IMAPFolder.ProtocolCommand() {
@Override
public Object doCommand(IMAPProtocol imapProtocol) throws ProtocolException {
try {
imapProtocol.simpleCommand("CREATE " + foldername, null);
} catch (Exception e) {
// Handle Exception
}
return null;
}
});
...