CVE-2021-44238
📋 TL;DR
AyaCMS 3.1.2 contains a remote code execution vulnerability in the admin module that allows attackers to execute arbitrary code on the server. This affects all systems running the vulnerable version of AyaCMS with the admin module accessible. Attackers can potentially take full control of affected web servers.
💻 Affected Systems
- AyaCMS
📦 What is this software?
Ayacms by Ayacms Project
⚠️ Risk & Real-World Impact
Worst Case
Complete server compromise allowing attackers to install malware, steal data, pivot to internal networks, and establish persistent backdoors.
Likely Case
Web server compromise leading to website defacement, data theft, and use as a platform for further attacks.
If Mitigated
Limited impact if proper network segmentation and access controls prevent exploitation attempts.
🎯 Exploit Status
Exploitation requires access to admin interface. Public proof-of-concept exists in GitHub issues.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.1.3 or later
Vendor Advisory: https://github.com/loadream/AyaCMS/issues/2
Restart Required: Yes
Instructions:
1. Backup current installation. 2. Download latest version from official repository. 3. Replace vulnerable files. 4. Restart web server. 5. Verify fix.
🔧 Temporary Workarounds
Restrict Admin Access
allBlock access to vulnerable admin endpoint using web server configuration
# Apache: RewriteRule ^/aya/module/admin/ust_tab_e\.inc\.php$ - [F,L]
# Nginx: location ~ /aya/module/admin/ust_tab_e\.inc\.php$ { deny all; }
Input Validation
allAdd input sanitization to prevent code injection
🧯 If You Can't Patch
- Implement strict network access controls to limit who can reach the admin interface
- Deploy web application firewall with RCE protection rules
🔍 How to Verify
Check if Vulnerable:
Check if /aya/module/admin/ust_tab_e.inc.php exists and version is 3.1.2Check Version:
grep -r 'version' /path/to/ayacms/ | grep -i '3.1.2'Verify Fix Applied:
Verify version is 3.1.3+ and test endpoint with safe payload📡 Detection & Monitoring
Log Indicators:
- POST requests to /aya/module/admin/ust_tab_e.inc.php with suspicious parameters
- Unusual process execution from web server user
Network Indicators:
- HTTP requests containing system commands in parameters
- Outbound connections from web server to unknown IPs
SIEM Query:
source="web_logs" AND uri="/aya/module/admin/ust_tab_e.inc.php" AND (param="system" OR param="exec" OR param="shell_exec")