CVE-2021-44935
📋 TL;DR
CVE-2021-44935 is an arbitrary user impersonation vulnerability in glFusion CMS that allows remote attackers to take over any user account without authentication. This affects all glFusion CMS v1.7.9 installations with the comment.php functionality enabled. Attackers can perform actions as any user, including administrators.
💻 Affected Systems
- glFusion CMS
📦 What is this software?
Glfusion by Glfusion
⚠️ Risk & Real-World Impact
Worst Case
Complete site compromise where attackers gain administrative privileges, modify content, install backdoors, steal sensitive data, and potentially pivot to other systems.
Likely Case
Account takeover leading to privilege escalation, data theft, content manipulation, and unauthorized access to user information.
If Mitigated
Limited impact if proper network segmentation, WAF rules, and monitoring are in place to detect and block exploitation attempts.
🎯 Exploit Status
Exploitation requires sending crafted requests to /public_html/comment.php. No authentication or user interaction needed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v1.7.10 and later
Vendor Advisory: https://github.com/glFusion/glfusion/issues/482
Restart Required: No
Instructions:
1. Backup your glFusion installation. 2. Download glFusion v1.7.10 or later from official sources. 3. Replace affected files with patched versions. 4. Verify comment.php has proper session validation.
🔧 Temporary Workarounds
Disable comment.php access
allTemporarily block access to the vulnerable file via web server configuration
# Apache: RewriteRule ^public_html/comment\.php$ - [F,L]
# Nginx: location ~ /public_html/comment\.php$ { deny all; }
Implement WAF rules
allAdd web application firewall rules to block exploitation attempts
# ModSecurity rule: SecRule REQUEST_URI "@contains comment.php" "id:1001,phase:1,deny"
🧯 If You Can't Patch
- Implement strict network access controls to limit who can access the glFusion instance
- Enable detailed logging and monitoring for suspicious activity on comment.php endpoints
🔍 How to Verify
Check if Vulnerable:
Check if running glFusion v1.7.9 and test if comment.php accepts crafted session manipulation requestsCheck Version:
Check glFusion admin panel or examine version.php fileVerify Fix Applied:
Verify glFusion version is v1.7.10+ and test that comment.php properly validates user sessions📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to comment.php
- Multiple failed authentication attempts followed by successful login from same IP
- User agent switching in session logs
Network Indicators:
- HTTP requests to comment.php with manipulated session/cookie parameters
- Unusual traffic patterns to comment.php endpoint
SIEM Query:
source="web_logs" AND uri="*/comment.php" AND (status=200 OR status=302) AND user_agent!="*bot*"