Bitrix galleries_recalc.php XSS
Description
The Bitrix content management system contains a Cross-Site Scripting (XSS) vulnerability in the galleries_recalc.php script. This flaw allows attackers to inject malicious JavaScript code that executes in the context of a victim's browser when they access the affected page. The vulnerability exists due to insufficient input validation and output encoding of user-supplied data.
Remediation
Take the following steps to remediate this vulnerability:
1. Upgrade Bitrix: Update to the latest stable version of Bitrix CMS immediately. Consult the official Bitrix release notes to identify the specific version that addresses this vulnerability.
2. Verify the Fix: After upgrading, test the galleries_recalc.php script to confirm that user input is properly sanitized and output is correctly encoded.
3. Implement Defense-in-Depth: While upgrading, consider implementing additional security controls:
• Enable Content Security Policy (CSP) headers to restrict the execution of inline scripts
• Implement HTTP-only and Secure flags on session cookies to prevent JavaScript access
• Deploy Web Application Firewall (WAF) rules to filter malicious input patterns
4. Review Custom Code: If you have customized the galleries_recalc.php file, ensure all modifications properly encode output using htmlspecialchars() or equivalent functions before displaying user-controlled data.
5. Monitor for Exploitation: Review web server logs for suspicious activity targeting galleries_recalc.php prior to patching to identify potential compromise.