CVE-2023-27733
📋 TL;DR
DedeCMS v5.7.106 contains a SQL injection vulnerability in the /dede/sys_sql_query.php component that allows authenticated attackers to execute arbitrary SQL commands. This affects administrators with access to the CMS backend. Successful exploitation could lead to data theft, modification, or deletion.
💻 Affected Systems
- DedeCMS
📦 What is this software?
Dedecms by Dedecms
⚠️ Risk & Real-World Impact
Worst Case
Complete database compromise including sensitive data exfiltration, privilege escalation to system-level access, or complete CMS takeover.
Likely Case
Database manipulation, extraction of user credentials and sensitive content, or installation of backdoors.
If Mitigated
Limited impact with proper input validation and database permissions, potentially only affecting non-sensitive data.
🎯 Exploit Status
Exploitation requires backend access but is straightforward once authenticated.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v5.7.107 or later
Vendor Advisory: https://www.dedecms.com/
Restart Required: No
Instructions:
1. Backup your database and files. 2. Download the latest version from the official DedeCMS website. 3. Replace the vulnerable /dede/sys_sql_query.php file with the patched version. 4. Verify the fix by testing the component.
🔧 Temporary Workarounds
Restrict Access to /dede/ Directory
allLimit access to the vulnerable component via web server configuration
# Apache: Add to .htaccess
<Files "sys_sql_query.php">
Order deny,allow
Deny from all
</Files>
# Nginx: Add to server block
location ~ /dede/sys_sql_query\.php$ {
deny all;
return 403;
}
Input Validation Filter
allAdd parameter sanitization to the vulnerable file
# Add to sys_sql_query.php before SQL execution
$query = preg_replace('/[^a-zA-Z0-9_\s]/', '', $_POST['query']);
🧯 If You Can't Patch
- Implement strict network segmentation to isolate the DedeCMS instance
- Enable detailed SQL query logging and monitor for suspicious database activity
🔍 How to Verify
Check if Vulnerable:
Check if /dede/sys_sql_query.php exists and accepts unsanitized SQL parameters. Test with a safe SQL query like 'SELECT 1' to confirm injection.Check Version:
Check /data/admin/ver.txt or view the CMS footer in admin panelVerify Fix Applied:
Attempt SQL injection with malicious payloads and verify they are rejected or sanitized. Check file modification dates and compare with patched version.📡 Detection & Monitoring
Log Indicators:
- Unusual SQL queries in database logs
- Multiple failed login attempts to /dede/ directory
- Unexpected database schema changes
Network Indicators:
- POST requests to /dede/sys_sql_query.php with SQL keywords
- Unusual database connection patterns
SIEM Query:
source="web_logs" AND uri="/dede/sys_sql_query.php" AND (body CONTAINS "UNION" OR body CONTAINS "SELECT *" OR body CONTAINS "DROP TABLE")🔗 References
- https://github.com/Ephemeral1y/Vulnerability/blob/master/DedeCMS/5.7.98/DedeCMS-v5.7.98-RCE.md
- https://sha999-crypto.github.io/2023/02/28/Dedecms%20background%20SQL%20injection%20vulnerability/
- https://github.com/Ephemeral1y/Vulnerability/blob/master/DedeCMS/5.7.98/DedeCMS-v5.7.98-RCE.md
- https://sha999-crypto.github.io/2023/02/28/Dedecms%20background%20SQL%20injection%20vulnerability/
