CVE-2019-13957
📋 TL;DR
This is a SQL injection vulnerability in Umbraco CMS that allows attackers to execute arbitrary SQL commands through the backoffice API. It affects Umbraco 7.3.8 installations with backoffice access, potentially compromising the entire database.
💻 Affected Systems
- Umbraco CMS
📦 What is this software?
Umbraco by Umbraco
⚠️ Risk & Real-World Impact
Worst Case
Complete database compromise including data theft, data manipulation, privilege escalation to admin, and potential remote code execution via database functions.
Likely Case
Database information disclosure, data manipulation, and potential backdoor installation through SQL injection.
If Mitigated
Limited impact if proper input validation and parameterized queries are implemented, with database permissions restricted.
🎯 Exploit Status
Exploit requires backoffice authentication, but SQL injection payloads are well-documented and easy to craft.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 7.3.9 and later
Vendor Advisory: https://our.umbraco.com/download/releases/738/
Restart Required: Yes
Instructions:
1. Backup your Umbraco installation and database. 2. Download Umbraco 7.3.9 or later from official site. 3. Replace affected files. 4. Restart application/web server. 5. Verify fix by testing the vulnerable endpoint.
🔧 Temporary Workarounds
Input Validation Filter
allAdd input validation to sanitize nodeName parameter before processing
Implement parameterized SQL queries in GetInpectSearch method
Add input validation: if (!IsValidInput(nodeName)) return BadRequest();
Access Restriction
allRestrict access to backoffice/PageWApprove/PageWApproveApi endpoint
Add IP whitelisting to web.config or application firewall rules
Implement additional authentication requirements for the endpoint
🧯 If You Can't Patch
- Implement web application firewall (WAF) with SQL injection rules
- Restrict database user permissions to minimum required
🔍 How to Verify
Check if Vulnerable:
Test the /umbraco/backoffice/PageWApprove/PageWApproveApi/GetInpectSearch endpoint with SQL injection payloads in nodeName parameterCheck Version:
Check Umbraco version in /umbraco/config/splashes/booting.aspx or web.configVerify Fix Applied:
After patching, test the same endpoint with SQL injection payloads and verify no database errors or unexpected behavior📡 Detection & Monitoring
Log Indicators:
- SQL syntax errors in application logs
- Unusual database queries from backoffice API
- Multiple failed login attempts followed by API access
Network Indicators:
- SQL keywords in HTTP POST parameters to backoffice endpoints
- Unusual database connection patterns
SIEM Query:
source="web_logs" AND uri="/umbraco/backoffice/PageWApprove/PageWApproveApi/GetInpectSearch" AND (param="*SELECT*" OR param="*UNION*" OR param="*INSERT*" OR param="*DELETE*")