CVE-2023-27091
📋 TL;DR
CVE-2023-27091 is an improper authentication vulnerability in TeaCMS 2.3.3 that allows attackers to bypass authorization controls via the id and keywords parameters, leading to privilege escalation. This affects all users running the vulnerable version of TeaCMS. Attackers can gain unauthorized access to administrative functions or sensitive data.
💻 Affected Systems
- XiaoBingby TeaCMS
📦 What is this software?
Teacms by Teacms Project
⚠️ Risk & Real-World Impact
Worst Case
Attackers gain full administrative control over the TeaCMS instance, allowing them to modify content, steal sensitive data, deploy backdoors, or compromise the underlying server.
Likely Case
Attackers escalate privileges to access administrative panels, modify user permissions, or exfiltrate sensitive information from the CMS database.
If Mitigated
With proper network segmentation and access controls, impact is limited to the TeaCMS application itself, though data exposure remains possible.
🎯 Exploit Status
Exploitation requires some authentication but not administrative privileges. The vulnerability is well-documented in public issue trackers with technical details.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.3.4 or later
Vendor Advisory: https://gitee.com/xiaobingby/TeaCMS/issues/I6GDRU
Restart Required: Yes
Instructions:
1. Backup your TeaCMS installation and database. 2. Download TeaCMS 2.3.4 or later from the official repository. 3. Replace the vulnerable files with the patched version. 4. Restart the web server and verify functionality.
🔧 Temporary Workarounds
Input Validation Filter
allImplement server-side validation to sanitize id and keywords parameters before processing.
# Add parameter validation in relevant PHP files
# Example: if(!is_numeric($_GET['id'])) { die('Invalid input'); }
Access Control Enhancement
allStrengthen session management and implement additional authorization checks for sensitive operations.
# Add role-based access control checks
# Example: if($_SESSION['role'] != 'admin') { header('Location: /unauthorized.php'); exit(); }
🧯 If You Can't Patch
- Implement strict network access controls to limit TeaCMS access to trusted IP addresses only.
- Deploy a web application firewall (WAF) with rules to block suspicious parameter manipulation attempts.
🔍 How to Verify
Check if Vulnerable:
Check if TeaCMS version is 2.3.3 by examining the version file or admin panel. Test if unauthorized parameter manipulation in id/keywords fields leads to privilege escalation.Check Version:
grep -r 'version' /path/to/teacms/ | grep -i '2.3.3'Verify Fix Applied:
After patching, verify the version shows 2.3.4 or later. Test that parameter manipulation no longer allows privilege escalation.📡 Detection & Monitoring
Log Indicators:
- Unusual parameter values in id or keywords fields
- Multiple failed authorization attempts followed by successful administrative access from same IP
- User privilege changes from non-admin to admin without proper workflow
Network Indicators:
- HTTP requests with manipulated id/keywords parameters to administrative endpoints
- Unusual traffic patterns to admin.php or similar sensitive files
SIEM Query:
source="web_logs" AND (uri_path="*admin*" OR uri_path="*manage*") AND (query_string="*id=*" OR query_string="*keywords=*") AND status=200