CVE-2020-36033
📋 TL;DR
This vulnerability allows attackers to execute arbitrary SQL commands through the id parameter in edituser.php in Water Billing System 1.0. This can lead to unauthorized data access, modification, or deletion. Organizations using this specific billing system version are affected.
💻 Affected Systems
- SourceCodester Water Billing System
📦 What is this software?
Water Billing System by Water Billing System Project
⚠️ Risk & Real-World Impact
Worst Case
Complete database compromise including data theft, data destruction, and potential server takeover via SQL injection leading to remote code execution.
Likely Case
Unauthorized access to sensitive user data, billing records, and potential privilege escalation to administrative accounts.
If Mitigated
Limited impact with proper input validation and database permissions, potentially only allowing data viewing without modification.
🎯 Exploit Status
SQL injection vulnerabilities are commonly exploited and tools like sqlmap can automate exploitation. The vulnerability is in a parameter that likely doesn't require authentication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: No official vendor advisory found
Restart Required: No
Instructions:
1. Check for updated version from SourceCodester. 2. If no patch available, implement parameterized queries in edituser.php. 3. Replace direct SQL concatenation with prepared statements. 4. Add input validation for the id parameter.
🔧 Temporary Workarounds
Web Application Firewall (WAF)
allDeploy a WAF with SQL injection protection rules to block malicious requests.
Input Validation Filter
allAdd server-side validation to only accept numeric values for the id parameter.
In edituser.php, add: if(!is_numeric($_GET['id'])) { die('Invalid input'); }
🧯 If You Can't Patch
- Isolate the system on a separate network segment with strict access controls
- Implement database-level controls: use least privilege accounts, enable audit logging, and restrict database permissions
🔍 How to Verify
Check if Vulnerable:
Test the edituser.php endpoint with SQL injection payloads like: edituser.php?id=1' OR '1'='1Check Version:
Check the software version in the application interface or configuration files.Verify Fix Applied:
Test with the same payloads and verify they are rejected or properly handled without SQL errors.📡 Detection & Monitoring
Log Indicators:
- Unusual SQL error messages in web server logs
- Multiple requests to edituser.php with suspicious parameters
- Database queries with UNION, SELECT, or other SQL keywords from web requests
Network Indicators:
- HTTP requests containing SQL keywords in URL parameters
- Unusual traffic patterns to the edituser.php endpoint
SIEM Query:
source="web_server_logs" AND (url="*edituser.php*" AND (param="*id=*'*" OR param="*id=*%27*" OR param="*id=* UNION *" OR param="*id=* SELECT *"))