CVE-2020-20915
📋 TL;DR
This is a critical SQL injection vulnerability in PublicCMS v4.0 that allows remote attackers to execute arbitrary SQL commands via the sql parameter in SysSiteAdminControl. Attackers can potentially read, modify, or delete database content, and in some configurations execute arbitrary code. All PublicCMS v4.0 installations with the vulnerable component exposed are affected.
💻 Affected Systems
- PublicCMS
📦 What is this software?
Publiccms by Publiccms
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise including arbitrary code execution, database destruction, and potential lateral movement to other systems.
Likely Case
Database compromise leading to data theft, data manipulation, or denial of service through database corruption.
If Mitigated
Limited impact with proper input validation and parameterized queries preventing SQL injection.
🎯 Exploit Status
The vulnerability is well-documented in GitHub issues with technical details that could be weaponized. SQL injection vulnerabilities are commonly exploited.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version after 4.0 (check latest release)
Vendor Advisory: https://github.com/sanluan/PublicCMS/issues/29
Restart Required: Yes
Instructions:
1. Backup your current installation and database. 2. Download the latest version of PublicCMS from the official repository. 3. Replace the vulnerable files with patched versions. 4. Restart the web server. 5. Verify the fix by testing the vulnerable endpoint.
🔧 Temporary Workarounds
Input Validation Filter
allImplement strict input validation to filter SQL injection patterns from the sql parameter
Modify SysSiteAdminControl to sanitize sql parameter input
Web Application Firewall
allDeploy WAF with SQL injection protection rules
Configure WAF to block requests containing SQL injection patterns in parameters
🧯 If You Can't Patch
- Implement network segmentation to isolate the vulnerable system from critical assets
- Deploy intrusion detection systems to monitor for SQL injection attempts
🔍 How to Verify
Check if Vulnerable:
Check if running PublicCMS version 4.0 and test the SysSiteAdminControl endpoint with SQL injection payloadsCheck Version:
Check PublicCMS version in admin panel or configuration filesVerify Fix Applied:
Test the SysSiteAdminControl endpoint with SQL injection payloads after patching to ensure they are rejected📡 Detection & Monitoring
Log Indicators:
- Unusual SQL queries in application logs
- Multiple failed login attempts or parameter manipulation in access logs
Network Indicators:
- HTTP requests containing SQL keywords in parameters
- Unusual database connection patterns
SIEM Query:
source="web_logs" AND (sql OR union OR select OR insert OR delete) AND parameter="sql"