CVE-2020-6138
📋 TL;DR
This CVE describes a critical SQL injection vulnerability in OS4Ed openSIS 7.3's password reset functionality. Attackers can exploit the 'uname' parameter in ResetUserInfo.php to execute arbitrary SQL commands, potentially compromising the entire database. All organizations running openSIS 7.3 are affected.
💻 Affected Systems
- OS4Ed openSIS
📦 What is this software?
Opensis by Os4ed
⚠️ Risk & Real-World Impact
Worst Case
Complete database compromise leading to data theft, privilege escalation, authentication bypass, and potential remote code execution on the underlying server.
Likely Case
Database information disclosure, user credential theft, and potential administrative access to the openSIS application.
If Mitigated
Limited impact with proper input validation, parameterized queries, and database permissions restricting SQL execution.
🎯 Exploit Status
SQL injection via HTTP request to /opensis/ResetUserInfo.php with malicious uname parameter.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 7.4 or later
Vendor Advisory: https://www.os4ed.com/
Restart Required: No
Instructions:
1. Upgrade openSIS to version 7.4 or later. 2. Apply vendor-provided patches if available. 3. Test the password reset functionality after upgrade.
🔧 Temporary Workarounds
Input Validation Filter
allImplement server-side input validation to sanitize the uname parameter.
Modify ResetUserInfo.php to validate uname parameter using regex or whitelist
WAF Rule
allDeploy web application firewall rules to block SQL injection patterns.
Add WAF rule to detect and block SQL injection attempts on /opensis/ResetUserInfo.php
🧯 If You Can't Patch
- Disable the password reset functionality temporarily
- Implement network segmentation to restrict access to the openSIS application
🔍 How to Verify
Check if Vulnerable:
Test the password reset page with SQL injection payloads in the uname parameter.Check Version:
Check openSIS version in application interface or configuration files.Verify Fix Applied:
Verify that SQL injection attempts no longer succeed and check openSIS version is 7.4+.📡 Detection & Monitoring
Log Indicators:
- Unusual SQL queries in database logs
- Multiple failed password reset attempts with suspicious parameters
Network Indicators:
- HTTP requests to /opensis/ResetUserInfo.php containing SQL keywords
SIEM Query:
source="web_logs" AND uri="/opensis/ResetUserInfo.php" AND (param="uname" AND value CONTAINS "' OR ")