CVE-2024-13918

Vulnerability Remediation/Mitigation Strategy: CVE-2024-13918 - Laravel Reflected XSS

Vulnerability ID: CVE-2024-13918

Description:

The Laravel framework, specifically versions between 11.9.0 and 11.35.1, is vulnerable to a reflected Cross-Site Scripting (XSS) attack. This vulnerability stems from improper encoding of request parameters within the debug-mode error page. When debug mode is enabled and an error occurs related to a user-supplied request parameter, the raw, unencoded value of that parameter is rendered within the error page’s HTML. An attacker can craft a malicious URL containing JavaScript code in a request parameter. When a user clicks this malicious link, the code will be executed in the user’s browser within the context of the Laravel application.

Severity:

• CVSS Score: 8.0 (High) based on the provided data.
• Impact: Successful exploitation of this vulnerability can lead to:
  • Account Takeover: An attacker could steal user credentials or session cookies.
  • Malware Distribution: The attacker could inject malicious scripts to redirect users to phishing sites or distribute malware.
  • Defacement: The attacker could alter the appearance of the website, potentially damaging its reputation.
  • Data Theft: The attacker could steal sensitive information displayed on the page.

Known Exploit:

The information provided indicates a vulnerability exists, but doesn’t explicitly describe a known, published exploit. However, given the nature of reflected XSS, an attacker could craft a malicious URL containing JavaScript payloads designed to execute upon being rendered in the debug error page. The exploit would involve tricking a user into clicking this crafted URL. The error page then becomes the vehicle for delivering and executing the XSS payload in the user’s browser.

Remediation Strategy:

1. Upgrade Laravel: The most effective solution is to upgrade your Laravel application to a version later than 11.35.1. Newer versions of Laravel likely contain the necessary fixes to properly encode request parameters in debug mode. Check the official Laravel release notes or security advisories for details on the fix.

2. Disable Debug Mode in Production: Critical: Ensure that the APP_DEBUG environment variable is set to false in your production environment. Debug mode should never be enabled on production servers. This is a general security best practice, not just specific to this vulnerability. Debug mode exposes sensitive information and facilitates exploitation.

   • Verify the .env file in your production environment:

         APP_DEBUG=false
     

3. Input Validation and Output Encoding: While upgrading/disabling debug mode is paramount, review your codebase for proper input validation and output encoding practices. This is a broader defense-in-depth strategy:

   • Input Validation: Validate all user-supplied input on the server-side. Do not rely solely on client-side validation. Ensure that input conforms to expected formats, data types, and lengths. Reject invalid input.

   • Output Encoding: Use proper output encoding techniques (e.g., HTML entity encoding) to sanitize data before rendering it in HTML. Laravel’s Blade templating engine provides mechanisms for automatic encoding, but it’s important to understand how they work and ensure they’re being used correctly. Use Blade templating directive {{ }} which automatically escapes the html.

4. Web Application Firewall (WAF): Implement a Web Application Firewall (WAF) that can detect and block XSS attacks. Configure the WAF with rules specifically designed to prevent XSS vulnerabilities. While not a substitute for patching, a WAF provides an additional layer of protection.

5. Content Security Policy (CSP): Implement a Content Security Policy (CSP) to restrict the sources from which the browser is allowed to load resources (e.g., scripts, stylesheets). A strong CSP can mitigate the impact of XSS attacks by preventing the execution of malicious scripts from untrusted sources.

6. Regular Security Audits and Penetration Testing: Conduct regular security audits and penetration testing to identify and address potential vulnerabilities in your Laravel application. This helps proactively discover security flaws before they can be exploited by attackers.

Mitigation Steps:

• Short Term (Immediate Actions):

  • Verify APP_DEBUG=false in production environment.
  • Implement a temporary WAF rule to block requests containing common XSS payloads in request parameters. (e.g., <script>, javascript:, onerror=)

• Long Term (Sustainable Solutions):

  • Upgrade Laravel to a patched version.
  • Enforce proper input validation and output encoding across the application.
  • Implement and maintain a robust CSP.
  • Schedule regular security audits and penetration testing.

Testing:

After implementing the remediation steps, thoroughly test the application to ensure that the vulnerability has been successfully mitigated. Specifically, test the error handling mechanisms with intentionally crafted malicious input to verify that the input is properly encoded and does not execute as JavaScript code. Use a security scanner and manual penetration testing to confirm the fix.

Reporting:

Document all steps taken to remediate the vulnerability, including the version of Laravel used, the changes made to the codebase, and the results of the testing. Retain this documentation for future reference and audit purposes.

Assigner

• sba-research <1e3a9e0f-5156-4bf8-b8a3-cc311bfc0f4a>

Date

• Published Date: 2025-03-10 10:15:10
• Updated Date: 2025-03-10 17:15:34

More Details

CVE-2024-13918