CVE-2018-16278
📋 TL;DR
This is an unauthenticated SQL injection vulnerability in PhpOpenSourceCMS (POSCMS) that allows attackers to execute arbitrary SQL commands. It affects phpkaiyuancms POSCMS version 3.2.0, potentially compromising the entire database. Any system running this vulnerable version is at risk.
💻 Affected Systems
- phpkaiyuancms PhpOpenSourceCMS (POSCMS)
📦 What is this software?
Phpopensourcecms by Phpkaiyuancms
⚠️ Risk & Real-World Impact
Worst Case
Complete database compromise including data theft, data destruction, privilege escalation to admin, and potential remote code execution via database functions.
Likely Case
Database information disclosure, authentication bypass, and data manipulation leading to site defacement or user data theft.
If Mitigated
Limited impact with proper input validation and parameterized queries in place, though the vulnerability still exists.
🎯 Exploit Status
The exploit is straightforward with publicly available details. Attackers can craft simple HTTP requests to trigger the SQL injection.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after V3.2.0
Vendor Advisory: https://github.com/howchen/howchen/issues/3
Restart Required: No
Instructions:
1. Upgrade to the latest version of POSCMS. 2. If upgrading is not possible, apply the patch from the GitHub issue. 3. Replace the vulnerable file diy/module/member/controllers/Api.php with the patched version.
🔧 Temporary Workarounds
Input Validation Filter
allAdd input validation to filter the 'dir' parameter in the ajax_save_draft function
Edit diy/module/member/controllers/Api.php and add parameter validation before using the dir parameter
WAF Rule
allImplement a web application firewall rule to block suspicious SQL injection patterns in the ajax_save_draft endpoint
Add WAF rule: Block requests to /diy/module/member/controllers/Api.php?ajax_save_draft containing SQL keywords in dir parameter
🧯 If You Can't Patch
- Disable the vulnerable ajax_save_draft function or restrict access to authenticated users only
- Implement network segmentation to isolate the CMS from critical databases and systems
🔍 How to Verify
Check if Vulnerable:
Check if the file diy/module/member/controllers/Api.php exists and contains the vulnerable ajax_save_draft function without proper input validation on the dir parameter.Check Version:
Check the CMS version in the admin panel or look for version information in configuration files.Verify Fix Applied:
Verify that the ajax_save_draft function now uses parameterized queries or proper input validation for the dir parameter.📡 Detection & Monitoring
Log Indicators:
- Unusual SQL errors in web server logs
- Multiple requests to /diy/module/member/controllers/Api.php with suspicious dir parameters
- Database connection errors or unusual query patterns
Network Indicators:
- HTTP POST/GET requests containing SQL injection payloads in the dir parameter
- Unusual traffic patterns to the ajax_save_draft endpoint
SIEM Query:
source="web_server" AND (uri="/diy/module/member/controllers/Api.php" AND (param="dir" AND value CONTAINS "UNION" OR value CONTAINS "SELECT" OR value CONTAINS "INSERT"))