CVE-2025-43737
📋 TL;DR
A reflected cross-site scripting (XSS) vulnerability in Liferay Portal/DXP allows authenticated attackers to inject malicious JavaScript via the backURL parameter. This could enable session hijacking, data theft, or unauthorized actions within authenticated sessions. Only authenticated users can exploit this vulnerability.
💻 Affected Systems
- Liferay Portal
- Liferay DXP
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attacker steals administrator session cookies, gains full administrative access to the portal, modifies content, accesses sensitive data, or deploys backdoors.
Likely Case
Attacker steals regular user session cookies, performs actions as that user, accesses their data, or redirects to phishing sites.
If Mitigated
With proper input validation and output encoding, malicious scripts are neutralized before execution, preventing exploitation.
🎯 Exploit Status
Exploitation requires authenticated access and social engineering to trick users into clicking malicious links.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Liferay Portal 7.4.3.133 or later; Liferay DXP 2025.Q2.9 or later, 2025.Q1.16 or later
Vendor Advisory: https://liferay.dev/portal/security/known-vulnerabilities/-/asset_publisher/jekt/content/CVE-2025-43737
Restart Required: No
Instructions:
1. Download the appropriate patch from Liferay's customer portal. 2. Apply the patch following Liferay's patch installation guide. 3. Verify the fix by testing the vulnerable parameter.
🔧 Temporary Workarounds
Input Validation Filter
allImplement a servlet filter to sanitize the _com_liferay_journal_web_portlet_JournalPortlet_backURL parameter
Custom Java filter implementation required - no single command
Content Security Policy
allImplement strict CSP headers to mitigate XSS impact
Add 'Content-Security-Policy: default-src 'self'; script-src 'self'' to web server configuration
🧯 If You Can't Patch
- Implement WAF rules to block malicious backURL parameter values
- Disable or restrict access to Journal Portlet for non-essential users
🔍 How to Verify
Check if Vulnerable:
Test by accessing Journal Portlet with backURL parameter containing test payload like: backURL=javascript:alert('XSS')Check Version:
Check Liferay version in Control Panel → Configuration → Server Administration → System InformationVerify Fix Applied:
After patching, retest with same payload; script should not execute and parameter should be sanitized📡 Detection & Monitoring
Log Indicators:
- HTTP requests containing 'backURL' parameter with JavaScript or suspicious content in access logs
Network Indicators:
- Unusual redirects from Journal Portlet URLs
- Requests with encoded JavaScript in URL parameters
SIEM Query:
web_access_logs | where url contains "backURL" and (url contains "javascript:" or url contains "<script>" or url contains encoded special characters)