CVE-2020-20298
📋 TL;DR
This is a critical remote code execution vulnerability in zzzphp CMS that allows attackers to execute arbitrary commands on the server through eval injection in template parsing. It affects all systems running zzzphp 1.7.2 with the vulnerable component accessible. Attackers can gain complete control of affected web servers.
💻 Affected Systems
- zzzphp CMS
📦 What is this software?
Zzzphp by Zzzcms
⚠️ Risk & Real-World Impact
Worst Case
Full server compromise allowing attackers to execute arbitrary commands, install malware, steal data, pivot to internal networks, and establish persistent backdoors.
Likely Case
Webshell deployment leading to data exfiltration, website defacement, cryptocurrency mining, or participation in botnets.
If Mitigated
Limited impact if proper network segmentation, WAF rules, and file integrity monitoring are in place to detect and block exploitation attempts.
🎯 Exploit Status
Public exploit code is available and exploitation requires minimal technical skill. Attackers can directly execute system commands without authentication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.7.3 or later
Vendor Advisory: https://github.com/zzzcms/zzzcms/issues
Restart Required: No
Instructions:
1. Backup your current installation. 2. Download the latest version from the official repository. 3. Replace the vulnerable zzz_template.php file. 4. Verify the fix by checking the version number.
🔧 Temporary Workarounds
Disable template parsing
linuxTemporarily disable the vulnerable template parsing functionality
mv zzz_template.php zzz_template.php.disabled
WAF rule implementation
allBlock eval injection patterns at the web application firewall
🧯 If You Can't Patch
- Implement strict input validation and sanitization for all template parameters
- Deploy network segmentation to isolate the vulnerable system from critical assets
🔍 How to Verify
Check if Vulnerable:
Check if zzzphp version is 1.7.2 and examine zzz_template.php for the vulnerable parserCommom methodCheck Version:
grep -r 'version' config.php or check admin panelVerify Fix Applied:
Verify the version is updated to 1.7.3+ and check that eval() calls in zzz_template.php are properly sanitized📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to template parsing endpoints
- Eval() function calls with suspicious parameters in PHP logs
- Webshell file creation in web directories
Network Indicators:
- HTTP requests containing eval() or system() patterns in parameters
- Outbound connections from web server to unknown IPs
SIEM Query:
source="web_logs" AND (eval OR system OR exec) AND uri="*template*"