CVE-2025-62254
📋 TL;DR
This vulnerability in Liferay Portal and DXP allows remote attackers to trigger denial of service attacks by exploiting the ComboServlet's lack of limits on file combination. Attackers can craft requests that force the server to generate extremely large responses, consuming resources and making the service unavailable. All organizations running affected Liferay versions are at risk.
💻 Affected Systems
- Liferay Portal
- Liferay DXP
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete service outage with resource exhaustion leading to server crashes and extended downtime.
Likely Case
Degraded performance and intermittent service disruptions affecting user access.
If Mitigated
Minimal impact with proper rate limiting, request filtering, and resource monitoring in place.
🎯 Exploit Status
Exploitation requires only web access and knowledge of vulnerable endpoint. No authentication needed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Liferay Portal 7.4.3.112+, Liferay DXP 2023.Q4.3+, 2023.Q3.6+, 7.4 update 93+, 7.3 update 36+
Vendor Advisory: https://liferay.dev/portal/security/known-vulnerabilities/-/asset_publisher/jekt/content/CVE-2025-62254
Restart Required: Yes
Instructions:
1. Download appropriate patch from Liferay customer portal. 2. Backup current installation. 3. Apply patch following Liferay's patch installation guide. 4. Restart Liferay server. 5. Verify patch application.
🔧 Temporary Workarounds
Web Application Firewall (WAF) Rules
allImplement WAF rules to block or limit requests to /combo endpoint with excessive parameters.
Reverse Proxy Rate Limiting
linuxConfigure rate limiting on reverse proxy (nginx, Apache) for /combo endpoint.
nginx example: limit_req_zone $binary_remote_addr zone=combo:10m rate=10r/s;
nginx location block: location ~* /combo { limit_req zone=combo burst=20; }
🧯 If You Can't Patch
- Implement strict rate limiting at network perimeter for /combo endpoint
- Monitor server resource usage and set alerts for abnormal memory/CPU spikes
🔍 How to Verify
Check if Vulnerable:
Check Liferay version via Control Panel → Configuration → Server Administration → System InformationCheck Version:
Check liferay-portal.xml or via Liferay UI: Control Panel → Configuration → Server AdministrationVerify Fix Applied:
Verify version is patched and test /combo endpoint with large parameter requests to confirm resource limits📡 Detection & Monitoring
Log Indicators:
- High frequency requests to /combo endpoint
- Large response sizes in access logs
- OutOfMemory errors in server logs
Network Indicators:
- Abnormal traffic patterns to /combo with many parameters
- Large HTTP responses from ComboServlet
SIEM Query:
source="liferay.logs" AND (uri_path="/combo" AND parameter_count>50) OR response_size>100MB