CVE-2021-44949
📋 TL;DR
CVE-2021-44949 is an access control vulnerability in glFusion CMS that allows unauthorized access to user management functions via the /public_html/users.php endpoint. This affects all glFusion CMS 1.7.9 installations, potentially allowing attackers to view, modify, or delete user accounts without proper authentication.
💻 Affected Systems
- glFusion CMS
📦 What is this software?
Glfusion by Glfusion
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of user accounts including administrative accounts, leading to full system takeover, data exfiltration, or website defacement.
Likely Case
Unauthorized access to user data, privilege escalation, or account takeover of regular users.
If Mitigated
Limited impact with proper network segmentation and access controls, though the vulnerability still exists.
🎯 Exploit Status
The vulnerability is simple to exploit with direct access to the vulnerable endpoint. Public discussion and proof-of-concept details are available in the GitHub issue.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.7.10 or later
Vendor Advisory: https://github.com/glFusion/glfusion/issues/487
Restart Required: No
Instructions:
1. Backup your glFusion installation and database. 2. Download glFusion 1.7.10 or later from the official repository. 3. Replace the vulnerable files with the patched version. 4. Verify the fix by testing the /users.php endpoint.
🔧 Temporary Workarounds
Block access to users.php
allTemporarily block access to the vulnerable endpoint using web server configuration.
# For Apache: add to .htaccess
<Files "users.php">
Order allow,deny
Deny from all
</Files>
# For Nginx: add to server block
location ~ /users\.php$ {
deny all;
return 403;
}
🧯 If You Can't Patch
- Implement strict network access controls to limit who can access the glFusion instance.
- Deploy a web application firewall (WAF) with rules to block unauthorized access to /users.php.
🔍 How to Verify
Check if Vulnerable:
Attempt to access /public_html/users.php without authentication. If you can access user management functions, the system is vulnerable.Check Version:
Check the version.php file in your glFusion installation or look at the admin panel version information.Verify Fix Applied:
After patching, attempt to access /public_html/users.php without authentication. You should receive an access denied error or be redirected to login.📡 Detection & Monitoring
Log Indicators:
- Unusual access patterns to /users.php from unauthenticated users
- Multiple failed authentication attempts followed by successful access to user management
Network Indicators:
- HTTP requests to /users.php without proper authentication headers or session cookies
SIEM Query:
source="web_server" AND (url="/users.php" OR url="/public_html/users.php") AND (user="-" OR auth_status="failed")