CVE-2021-43506
📋 TL;DR
This CVE describes an SQL injection vulnerability in the Simple Client Management System 1.0, allowing attackers to manipulate the password parameter in Login.php to execute arbitrary SQL commands. It affects users of this specific software version, potentially leading to unauthorized access or data breaches.
💻 Affected Systems
- Sourcecodester Simple Client Management System
📦 What is this software?
Simple Client Management System by Simple Client Management System Project
⚠️ Risk & Real-World Impact
Worst Case
Full database compromise, including data theft, modification, or deletion, and potential remote code execution if database permissions allow.
Likely Case
Authentication bypass, unauthorized access to client data, and extraction of sensitive information from the database.
If Mitigated
Limited impact if input validation and parameterized queries are enforced, reducing risk to minor data exposure.
🎯 Exploit Status
Exploitation is straightforward via the login page, with public proof-of-concept details available in the provided references.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: No
Instructions:
No official patch is known; consider applying workarounds or upgrading to a secure version if released by the vendor.
🔧 Temporary Workarounds
Implement Input Validation and Sanitization
allAdd server-side validation to sanitize the password parameter, rejecting malicious SQL characters.
Modify Login.php to use prepared statements or escape user inputs.
Use Web Application Firewall (WAF)
allDeploy a WAF to block SQL injection attempts at the network level.
Configure WAF rules to detect and block SQL injection patterns in login requests.
🧯 If You Can't Patch
- Isolate the system from the internet to reduce external attack surface.
- Implement strict access controls and monitor for suspicious login attempts.
🔍 How to Verify
Check if Vulnerable:
Test the login page with SQL injection payloads in the password field and observe if database errors or unauthorized access occurs.Check Version:
Check the software version in the system's admin panel or configuration files; for web-based systems, inspect source code or documentation.Verify Fix Applied:
After applying workarounds, retest with SQL injection payloads to ensure they are blocked and no unauthorized access is possible.📡 Detection & Monitoring
Log Indicators:
- Unusual SQL error messages in application logs, multiple failed login attempts with SQL-like strings.
Network Indicators:
- HTTP POST requests to Login.php containing SQL keywords or special characters in the password parameter.
SIEM Query:
Example: 'source="web_logs" AND url="*Login.php*" AND request_body="*password=*SELECT*OR*'*"'