1. Introduction
Cross-Site Scripting (XSS) is a vulnerability that allows attackers to inject malicious scripts into web pages viewed by other users. This can lead to account takeover, data theft, and website defacement. XSS vulnerabilities commonly affect websites and web applications that process user input without proper validation or sanitisation. A successful exploit could compromise the confidentiality, integrity, and availability of a web application.
2. Technical Explanation
XSS occurs when an application includes untrusted data in its HTML output. The scanner detected that it’s possible to inject an arbitrary URL into the `src` attribute of a script tag, leading to reflected XSS. An attacker can craft a malicious URL containing JavaScript code and trick a user into visiting it. When the user visits the page, their browser executes the injected script.
- Exploit mechanism: An attacker crafts a URL with a malicious payload within the `` to the end of URLs and observe if an alert box appears in your browser.
- Scanning: Use scanners like OWASP ZAP or Burp Suite’s scanner, looking for XSS signatures. These tools may identify this vulnerability as CWE-79.
- Logs and evidence: Examine web server logs for requests containing `` to the end of URLs. The alert box should no longer appear in your browser, indicating successful mitigation.
- Re-test: Re-run the scanner used for detection and confirm that it no longer identifies any XSS vulnerabilities.
- Monitoring: Monitor web server logs for suspicious requests containing `