permissions := strconv.Atoi(os.Getenv("filePermissions"));
fMode := os.FileMode(permissions)
os.chmod(filePath, fMode);
...
String permissionMask = System.getProperty("defaultFileMask");
Path filePath = userFile.toPath();
...
Set<PosixFilePermission> perms = PosixFilePermissions.fromString(permissionMask);
Files.setPosixFilePermissions(filePath, perms);
...
$rName = $_GET['publicReport'];
chmod("/home/". authenticateUser . "/public_html/" . rName,"0755");
...
publicReport, such as "../../localuser/public_html/.htpasswd", the application will make the specified file readable to the attacker.
...
$mask = $CONFIG_TXT['perms'];
chmod($filename,$mask);
...
permissions = os.getenv("filePermissions");
os.chmod(filePath, permissions);
...
...
rName = req['publicReport']
File.chmod("/home/#{authenticatedUser}/public_html/#{rName}", "0755")
...
publicReport, such as "../../localuser/public_html/.htpasswd", the application will make the specified file readable to the attacker.
...
mask = config_params['perms']
File.chmod(filename, mask)
...
services-config.xml descriptor file specifies a "Logging" XML element to describe various aspects of logging. It looks like the following:
<logging>
<target class="flex.messaging.log.ConsoleTarget" level="Debug">
<properties>
<prefix>[BlazeDS]</prefix>
<includeDate>false</includeDate>
<includeTime>false</includeTime>
<includeLevel>false</includeLevel>
<includeCategory>false</includeCategory>
</properties>
<filters>
<pattern>Endpoint.*</pattern>
<pattern>Service.*</pattern>
<pattern>Configuration</pattern>
</filters>
</target>
</logging>
target tag takes an optional attribute called level, which indicates the log level. If the debug level is set to too detailed a level, your application may write sensitive data to the log file.sprintf(), FormatMessageW(), or syslog().snprintf().
int main(int argc, char **argv){
char buf[128];
...
snprintf(buf,128,argv[1]);
}
%x, than the function takes as arguments to be formatted. (In this example, the function takes no arguments to be formatted.) By using the %n formatting directive, the attacker may write to the stack, causing snprintf() to write the number of bytes output thus far to the specified argument (rather than reading a value from the argument, which is the intended behavior). A sophisticated version of this attack will use four staggered writes to completely control the value of a pointer on the stack.
printf("%d %d %1$d %1$d\n", 5, 9);
5 9 5 5
Example 1.syslog() function is sometimes used as follows:
...
syslog(LOG_ERR, cmdBuf);
...
syslog() is a format string, any formatting directives included in cmdBuf are interpreted as described in Example 1.syslog():
...
syslog(LOG_ERR, "%s", cmdBuf);
...
sprintf(), FormatMessageW(), syslog(), NSLog, or NSString.stringWithFormatExample 1: The following code utilizes a command line argument as a format string in NSString.stringWithFormat:.
int main(int argc, char **argv){
char buf[128];
...
[NSString stringWithFormat:argv[1], argv[2] ];
}
%x, than the function takes as arguments to be formatted. (In this example, the function takes no arguments to be formatted.)
printf("%d %d %1$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);
...
}
script tag.
<script src="http://www.example.com/js/fancyWidget.js"></script>
www.example.com, then the site is dependent upon www.example.com to serve up correct and non-malicious code. If attackers can compromise www.example.com, then they can alter the contents of fancyWidget.js to subvert the security of the site. They could, for example, add code to fancyWidget.js to steal a user's confidential data.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
...
CC or BCC that they can use to leak the mail contents to themselves or use the mail server as a spam bot.CC header with a list of email addresses to spam anonymously because the email is sent from the victim's server.
func handler(w http.ResponseWriter, r *http.Request) {
subject := r.FormValue("subject")
body := r.FormValue("body")
auth := smtp.PlainAuth("identity", "user@example.com", "password", "mail.example.com")
to := []string{"recipient@example.net"}
msg := []byte("To: " + recipient1 + "\r\n" + subject + "\r\n" + body + "\r\n")
err := smtp.SendMail("mail.example.com:25", auth, "sender@example.org", to, msg)
if err != nil {
log.Fatal(err)
}
}
...
subject: [Contact us query] Page not working
...
subject does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Congratulations!! You won the lottery!!!\r\ncc:victim1@mail.com,victim2@mail.com ...", then the SMTP headers would be of the following form:
...
subject: [Contact us query] Congratulations!! You won the lottery
cc: victim1@mail.com,victim2@mail.com
...
CC or BCC that they can use to leak the mail contents to themselves or use the mail server as a spam bot.CC header with a list of email addresses to spam anonymously since the email will be sent from the victim server.
String subject = request.getParameter("subject");
String body = request.getParameter("body");
MimeMessage message = new MimeMessage(session);
message.setFrom(new InternetAddress("webform@acme.com"));
message.setRecipients(Message.RecipientType.TO, InternetAddress.parse("support@acme.com"));
message.setSubject("[Contact us query] " + subject);
message.setText(body);
Transport.send(message);
...
subject: [Contact us query] Page not working
...
subject does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Congratulations!! You won the lottery!!!\r\ncc:victim1@mail.com,victim2@mail.com ...", then the SMTP headers would be of the following form:
...
subject: [Contact us query] Congratulations!! You won the lottery
cc: victim1@mail.com,victim2@mail.com
...
CC or BCC that they can use to leak the mail contents to themselves or use the mail server as a spam bot.CC header with a list of email addresses to spam anonymously since the email will be sent from the victim server.
$subject = $_GET['subject'];
$body = $_GET['body'];
mail("support@acme.com", "[Contact us query] " . $subject, $body);
...
subject: [Contact us query] Page not working
...
subject does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Congratulations!! You won the lottery!!!\r\ncc:victim1@mail.com,victim2@mail.com ...", then the SMTP headers would be of the following form:
...
subject: [Contact us query] Congratulations!! You won the lottery
cc: victim1@mail.com,victim2@mail.com
...
CC or BCC that they can use to leak the mail contents to themselves or use the mail server as a spam bot.CC header with a list of email addresses to spam anonymously since the email will be sent from the victim server.
body = request.GET['body']
subject = request.GET['subject']
session = smtplib.SMTP(smtp_server, smtp_tls_port)
session.ehlo()
session.starttls()
session.login(username, password)
headers = "\r\n".join(["from: webform@acme.com",
"subject: [Contact us query] " + subject,
"to: support@acme.com",
"mime-version: 1.0",
"content-type: text/html"])
content = headers + "\r\n\r\n" + body
session.sendmail("webform@acme.com", "support@acme.com", content)
...
subject: [Contact us query] Page not working
...
subject does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Congratulations!! You won the lottery!!!\r\ncc:victim1@mail.com,victim2@mail.com ...", then the SMTP headers would be of the following form:
...
subject: [Contact us query] Congratulations!! You won the lottery
cc: victim1@mail.com,victim2@mail.com
...
...
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.allowBackup attribute to true (the default value) and defining the backupAgent attribute on the <application> tag.Environment.getExternalStorageDirectory() returns a reference to the Android device's external storage. private void WriteToFile(String what_to_write) {
try{
File root = Environment.getExternalStorageDirectory();
if(root.canWrite()) {
File dir = new File(root + "write_to_the_SDcard");
File datafile = new File(dir, number + ".extension");
FileWriter datawriter = new FileWriter(datafile);
BufferedWriter out = new BufferedWriter(datawriter);
out.write(what_to_write);
out.close();
}
}
}
kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly:kSecAttrAccessibleAlways:kSecAttrAccessibleWhenPasscodeSetThisDeviceOnly:kSecAttrAccessibleAlwaysThisDeviceOnly:kSecAttrAccessibleWhenUnlocked:kSecAttrAccessibleWhenUnlockedThisDeviceOnly:ThisDeviceOnly will be backed up to iCloud and backed up to iTunes even if using unencrypted backups which can be restored to any device. Depending on how sensitive and private the stored data is, this may raise a privacy concern.
...
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
NSData *token = [@"secret" dataUsingEncoding:NSUTF8StringEncoding];
// Configure KeyChain Item
[dict setObject:(__bridge id)kSecClassGenericPassword forKey:(__bridge id) kSecClass];
[dict setObject:token forKey:(__bridge id)kSecValueData];
...
[dict setObject:(__bridge id)kSecAttrAccessibleWhenUnlocked forKey:(__bridge id) kSecAttrAccessible];
OSStatus error = SecItemAdd((__bridge CFDictionaryRef)dict, NULL);
...
kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly:kSecAttrAccessibleAlways:kSecAttrAccessibleWhenPasscodeSetThisDeviceOnly:kSecAttrAccessibleAlwaysThisDeviceOnly:kSecAttrAccessibleWhenUnlocked:kSecAttrAccessibleWhenUnlockedThisDeviceOnly:ThisDeviceOnly will be backed up to iCloud and backed up to iTunes even if using unencrypted backups which can be restored to any device. Depending on how sensitive and private the stored data is, this may raise a privacy concern.
...
// Configure KeyChain Item
let token = "secret"
var query = [String : AnyObject]()
query[kSecClass as String] = kSecClassGenericPassword
query[kSecValueData as String] = token as AnyObject?
...
query[kSecAttrAccessible as String] = kSecAttrAccessibleWhenUnlocked
SecItemAdd(query as CFDictionary, nil)
...
protected void onCreate(Bundle savedInstanceState) {
...
try {
File httpCacheDir = new File(context.getExternalCacheDir(), "http");
long httpCacheSize = 10 * 1024 * 1024; // 10 MiB
HttpResponseCache.install(httpCacheDir, httpCacheSize);
} catch (IOException e) {
Log.i(TAG, "HTTP response cache installation failed:" + e);
}
}
protected void onStop() {
...
HttpResponseCache cache = HttpResponseCache.getInstalled();
if (cache != null) {
cache.flush();
}
}
{app ID}/Library/Caches/com.mycompany.myapp/Cache.db* files.{app ID}/Library/Caches/com.mycompany.myapp/Cache.db* files.{app ID}/Library/Caches/com.mycompany.myapp/Cache.db* files. diskCapacity or memoryCapacity properties of the URLCache class to 0, they may be effectively disabling the HTTP(S) response cache system. However, the NSURLCache documentation states that both the on-disk and in-memory caches will be truncated to the configured sizes only if the device runs low on memory or disk space. Both settings are meant to be used by the system to free system resources and improve performance, not as a security control.{app ID}/Library/Caches/com.mycompany.myapp/Cache.db* files. diskCapacity or memoryCapacity properties of the URLCache class to 0, they may be effectively disabling the HTTP(S) response cache system. However, the NSURLCache documentation states that both the on-disk and in-memory caches will be truncated to the configured sizes only if the device runs low on memory or disk space. Both settings are meant to be used by the system to free system resources and improve performance, not as a security control.NSFileManager as constants meant to be assigned as the value for the NSFileProtectionKey key in an NSDictionary associated with the NSFileManager instance, and files can be created or have their data protection class modified through use of NSFileManager functions including setAttributes:ofItemAtPath:error:, attributesOfItemAtPath:error:, and createFileAtPath:contents:attributes:. In addition, corresponding Data Protection constants are defined for NSData objects as NSDataWritingOptions that can be passed as the options argument to NSData functions writeToURL:options:error: and writeToFile:options:error:. The definitions for the various Data Protection class constants for NSFileManager and NSData are as follows:NSFileProtectionComplete, NSDataWritingFileProtectionComplete:NSFileProtectionCompleteUnlessOpen, NSDataWritingFileProtectionCompleteUnlessOpen:NSFileProtectionCompleteUntilFirstUserAuthentication, NSDataWritingFileProtectionCompleteUntilFirstUserAuthentication:NSFileProtectionNone, NSDataWritingFileProtectionNone:NSFileProtectionCompleteUnlessOpen or NSFileProtectionCompleteUntilFirstUserAuthentication will afford it encryption using a key derived from the user's passcode and the device's UID, the data will still remain accessible under certain circumstances. As such, usages of NSFileProtectionCompleteUnlessOpen or NSFileProtectionCompleteUntilFirstUserAuthentication should be carefully reviewed to determine if further protection with NSFileProtectionComplete is warranted.Example 2: In the following example, the given data is only protected until the user powers on the device and provides their passcode for the first time (until the next reboot):
...
filepath = [self.GetDocumentDirectory stringByAppendingPathComponent:self.setFilename];
...
NSDictionary *protection = [NSDictionary dictionaryWithObject:NSFileProtectionCompleteUntilFirstUserAuthentication forKey:NSFileProtectionKey];
...
[[NSFileManager defaultManager] setAttributes:protection ofItemAtPath:filepath error:nil];
...
BOOL ok = [testToWrite writeToFile:filepath atomically:YES encoding:NSUnicodeStringEncoding error:&err];
...
...
filepath = [self.GetDocumentDirectory stringByAppendingPathComponent:self.setFilename];
...
NSData *textData = [textToWrite dataUsingEncoding:NSUnicodeStingEncoding];
...
BOOL ok = [textData writeToFile:filepath options:NSDataWritingFileProtectionCompleteUntilFirstUserAuthentication error:&err];
...
NSFileManager as constants meant to be assigned as the value for the NSFileProtectionKey key in a Dictionary associated with the NSFileManager instance, and files can be created or have their data protection class modified through use of NSFileManager functions including setAttributes(_:ofItemAtPath:), attributesOfItemAtPath(_:), and createFileAtPath(_:contents:attributes:). In addition, corresponding Data Protection constants are defined for NSData objects in the NSDataWritingOptions enum that can be passed as the options argument to NSData functions
writeToFile(_:options:)NSFileManager and NSData are as follows:NSFileProtectionComplete, NSDataWritingOptions.DataWritingFileProtectionComplete:NSFileProtectionCompleteUnlessOpen, NSDataWritingOptions.DataWritingFileProtectionCompleteUnlessOpen:NSFileProtectionCompleteUntilFirstUserAuthentication, NSDataWritingOptions.DataWritingFileProtectionCompleteUntilFirstUserAuthentication:NSFileProtectionNone, NSDataWritingOptions.DataWritingFileProtectionNone:NSFileProtectionCompleteUnlessOpen or NSFileProtectionCompleteUntilFirstUserAuthentication will afford it encryption using a key derived from the user's passcode and the device's UID, the data will still remain accessible under certain circumstances. As such, usages of NSFileProtectionCompleteUnlessOpen or NSFileProtectionCompleteUntilFirstUserAuthentication should be carefully reviewed to determine if further protection with NSFileProtectionComplete is warranted.Example 2: In the following example, the given data is only protected until the user powers on the device and provides their passcode for the first time (until the next reboot):
...
let documentsPath = NSURL(fileURLWithPath: NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0])
let filename = "\(documentsPath)/tmp_activeTrans.txt"
let protection = [NSFileProtectionKey: NSFileProtectionCompleteUntilFirstUserAuthentication]
do {
try NSFileManager.defaultManager().setAttributes(protection, ofItemAtPath: filename)
} catch let error as NSError {
NSLog("Unable to change attributes: \(error.debugDescription)")
}
...
BOOL ok = textToWrite.writeToFile(filename, atomically:true)
...
...
let documentsPath = NSURL(fileURLWithPath: NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0])
let filename = "\(documentsPath)/tmp_activeTrans.txt"
...
BOOL ok = textData.writeToFile(filepath, options: .DataWritingFileProtectionCompleteUntilFirstUserAuthentication);
...
kSecAttrAccessible key in the Keychain attribute dictionary. The definitions for the various Keychain accessibility constants are as follows:kSecAttrAccessibleAfterFirstUnlock:kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly:kSecAttrAccessibleAlways:kSecAttrAccessibleWhenPasscodeSetThisDeviceOnly:kSecAttrAccessibleAlwaysThisDeviceOnly:kSecAttrAccessibleWhenUnlocked:kSecAttrAccessibleWhenUnlockedThisDeviceOnly:kSecAttrAccessibleAfterFirstUnlock will afford it encryption using a key derived from the user's passcode and the device's UID, the data will still remain accessible under certain circumstances. As such, usages of kSecAttrAccessibleAfterFirstUnlock should be carefully reviewed to determine if further protection is warranted.
...
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
NSData *token = [@"secret" dataUsingEncoding:NSUTF8StringEncoding];
// Configure KeyChain Item
[dict setObject:(__bridge id)kSecClassGenericPassword forKey:(__bridge id) kSecClass];
[dict setObject:token forKey:(__bridge id)kSecValueData];
...
[dict setObject:(__bridge id)kSecAttrAccessibleAfterFirstUnlock forKey:(__bridge id) kSecAttrAccessible];
OSStatus error = SecItemAdd((__bridge CFDictionaryRef)dict, NULL);
...
kSecAttrAccessible key in the Keychain attribute dictionary. The definitions for the various Keychain accessibility constants are as follows:kSecAttrAccessibleAfterFirstUnlock:kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly:kSecAttrAccessibleAlways:kSecAttrAccessibleWhenPasscodeSetThisDeviceOnly:kSecAttrAccessibleAlwaysThisDeviceOnly:kSecAttrAccessibleWhenUnlocked:kSecAttrAccessibleWhenUnlockedThisDeviceOnly:kSecAttrAccessibleAfterFirstUnlock will afford it encryption using a key derived from the user's passcode and the device's UID, the data will still remain accessible under certain circumstances. As such, usages of kSecAttrAccessibleAfterFirstUnlock should be carefully reviewed to determine if further protection is warranted.
...
// Configure KeyChain Item
let token = "secret"
var query = [String : AnyObject]()
query[kSecClass as String] = kSecClassGenericPassword
query[kSecValueData as String] = token as AnyObject?
...
query[kSecAttrAccessible as String] = kSecAttrAccessibleAfterFirstUnlock
SecItemAdd(query as CFDictionary, nil)
...