CVE-2021-36424
📋 TL;DR
This critical vulnerability in phpwcms allows remote attackers to execute arbitrary code during the installation process by manipulating the database user field. It affects all systems running phpwcms 1.9.25 that are either being installed or reinstalled. Attackers can gain complete control of affected systems without authentication.
💻 Affected Systems
- phpwcms
📦 What is this software?
Phpwcms by Phpwcms
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with remote code execution leading to data theft, ransomware deployment, or creation of persistent backdoors.
Likely Case
Web server compromise leading to website defacement, data exfiltration, or use as a foothold for lateral movement within the network.
If Mitigated
Limited impact if installation is already complete and system is properly hardened with input validation and least privilege.
🎯 Exploit Status
Exploitation is straightforward - attackers can inject malicious code into the database user field during installation setup.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.9.26
Vendor Advisory: https://github.com/slackero/phpwcms/issues/310
Restart Required: No
Instructions:
1. Upgrade phpwcms to version 1.9.26 or later. 2. If already installed, ensure no reinstallation is performed with vulnerable version. 3. Verify installation files are from trusted source.
🔧 Temporary Workarounds
Input Validation During Installation
allManually validate database user field input during installation to prevent code injection
Isolate Installation Environment
allPerform installation in isolated network segment with restricted internet access
🧯 If You Can't Patch
- Ensure installation is complete and never reinstall with vulnerable version
- Implement network segmentation to isolate phpwcms installation environment
🔍 How to Verify
Check if Vulnerable:
Check phpwcms version in admin panel or look for version 1.9.25 in source filesCheck Version:
Check includes/inc_tool/global.inc.php or admin interface for version numberVerify Fix Applied:
Verify phpwcms version is 1.9.26 or later and installation process is complete📡 Detection & Monitoring
Log Indicators:
- Unusual database connection attempts during installation
- Unexpected PHP code execution in installation logs
Network Indicators:
- HTTP requests to installation scripts with suspicious parameters
- Outbound connections from installation process
SIEM Query:
source="phpwcms" AND ("install" OR "setup") AND ("db_user" OR "database") AND suspicious_patterns