CVE-2021-40280
📋 TL;DR
An SQL injection vulnerability exists in zzcms versions 8.2, 8.3, 2020, and 2021 through the id parameter in admin/dl_sendmail.php. This allows attackers to execute arbitrary SQL commands on the database. Organizations running affected zzcms versions are vulnerable.
💻 Affected Systems
- zzcms
📦 What is this software?
Zzcms by Zzcms
Zzcms by Zzcms
Zzcms by Zzcms
Zzcms by Zzcms
⚠️ Risk & Real-World Impact
Worst Case
Complete database compromise leading to data theft, data manipulation, or full system takeover via SQL injection to RCE chaining.
Likely Case
Unauthorized data access, modification, or deletion from the zzcms database.
If Mitigated
Limited impact with proper input validation and WAF rules blocking SQL injection patterns.
🎯 Exploit Status
Exploit requires admin authentication but SQL injection is straightforward once authenticated.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None found
Restart Required: No
Instructions:
1. Check for official patch from zzcms vendor
2. If no patch, implement input validation and parameterized queries
3. Apply workarounds listed below
🔧 Temporary Workarounds
Input Validation Filter
allAdd input validation to sanitize the id parameter before processing
// In admin/dl_sendmail.php, add: $id = intval($_GET['id']);
WAF Rule Implementation
allDeploy web application firewall rules to block SQL injection patterns
# Example ModSecurity rule: SecRule ARGS:id "@detectSQLi" "id:1001,phase:2,deny"
🧯 If You Can't Patch
- Restrict access to admin/dl_sendmail.php endpoint using IP whitelisting
- Implement database user with minimal privileges for the application
🔍 How to Verify
Check if Vulnerable:
Test the id parameter in admin/dl_sendmail.php with SQL injection payloads like ' OR '1'='1Check Version:
Check zzcms version in admin interface or config filesVerify Fix Applied:
Verify that SQL injection payloads no longer execute and return proper error handling📡 Detection & Monitoring
Log Indicators:
- SQL syntax errors in web server logs
- Multiple failed login attempts followed by admin/dl_sendmail.php access
Network Indicators:
- HTTP requests to admin/dl_sendmail.php with SQL keywords in parameters
SIEM Query:
source="web_logs" AND uri="*/admin/dl_sendmail.php*" AND (param="*id=*OR*" OR param="*id=*UNION*" OR param="*id=*SELECT*")