CVE-2019-5893
📋 TL;DR
CVE-2019-5893 is a critical SQL injection vulnerability in Nelson Open Source ERP v6.3.1 that allows attackers to execute arbitrary SQL commands via the db/utils/query/data.xml query parameter. This affects all organizations running the vulnerable version of Nelson ERP, potentially exposing sensitive database information.
💻 Affected Systems
- Nelson Open Source ERP
📦 What is this software?
Open Source Erp by Nelson It
⚠️ Risk & Real-World Impact
Worst Case
Complete database compromise including data theft, data manipulation, authentication bypass, and potential remote code execution through database functions.
Likely Case
Unauthorized access to sensitive business data, customer information, financial records, and potential data exfiltration.
If Mitigated
Limited impact with proper input validation, parameterized queries, and network segmentation in place.
🎯 Exploit Status
Multiple public exploit scripts are available, making this trivial to exploit even for novice attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v6.3.2 or later
Vendor Advisory: https://github.com/nelson-ERP/nelson/releases
Restart Required: Yes
Instructions:
1. Backup your database and application files. 2. Download and install Nelson ERP v6.3.2 or later from the official repository. 3. Replace all existing files with the patched version. 4. Restart the web server and application services.
🔧 Temporary Workarounds
Input Validation Filter
allImplement strict input validation for the query parameter to block SQL injection attempts.
Modify db/utils/query/data.xml handler to sanitize all input parameters
WAF Rule Implementation
allDeploy web application firewall rules to block SQL injection patterns.
Add WAF rule: deny requests containing SQL keywords in query parameters
🧯 If You Can't Patch
- Isolate the Nelson ERP system from the internet and restrict access to authorized users only.
- Implement network segmentation to limit database access from the application server.
🔍 How to Verify
Check if Vulnerable:
Test by sending a SQL injection payload to the /db/utils/query/data.xml endpoint with a malicious query parameter.Check Version:
Check the application version in the admin panel or review the application's version file.Verify Fix Applied:
Attempt the same SQL injection test after patching; it should return an error or no data instead of executing the SQL.📡 Detection & Monitoring
Log Indicators:
- Unusual SQL queries in application logs
- Multiple failed login attempts followed by SQL injection patterns
- Access to db/utils/query/data.xml with suspicious parameters
Network Indicators:
- HTTP requests to /db/utils/query/data.xml containing SQL keywords like UNION, SELECT, INSERT
SIEM Query:
source="web_logs" AND uri="/db/utils/query/data.xml" AND (query="*SELECT*" OR query="*UNION*" OR query="*INSERT*")