CVE-2021-40247
📋 TL;DR
This SQL injection vulnerability in the Budget and Expense Tracker System allows attackers to execute arbitrary SQL commands through the username field during authentication. Attackers can potentially access, modify, or delete database contents. Any organization using this specific PHP application version is affected.
💻 Affected Systems
- Budget and Expense Tracker System by oretnom23
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete database compromise including data theft, data destruction, authentication bypass, and potential remote code execution via database functions.
Likely Case
Unauthorized data access, credential theft, and potential privilege escalation within the application.
If Mitigated
Limited impact with proper input validation and database permissions restricting damage to the application's database only.
🎯 Exploit Status
SQL injection in authentication endpoint requires no authentication, making exploitation trivial with available PoCs.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None available
Restart Required: No
Instructions:
No official patch available. Consider replacing with alternative software or implementing custom fixes.
🔧 Temporary Workarounds
Input Validation and Parameterized Queries
allImplement proper input validation and use prepared statements/parameterized queries for all database interactions.
Modify PHP code to use PDO or mysqli prepared statements
Web Application Firewall (WAF)
allDeploy WAF with SQL injection rules to block malicious payloads.
Configure WAF rules to detect and block SQL injection patterns
🧯 If You Can't Patch
- Isolate the application behind strict network controls and limit database permissions
- Implement additional authentication layers and monitor for suspicious login attempts
🔍 How to Verify
Check if Vulnerable:
Test login form with SQL injection payloads like ' OR '1'='1 in username field and observe database errors or unexpected behavior.Check Version:
Check application files for version indicators or review source code headers.Verify Fix Applied:
Attempt SQL injection payloads and verify they are rejected or properly sanitized without database errors.📡 Detection & Monitoring
Log Indicators:
- Unusual SQL syntax in authentication logs
- Multiple failed login attempts with SQL-like patterns
- Database error messages in application logs
Network Indicators:
- HTTP POST requests to login endpoint containing SQL keywords
- Unusual database query patterns from web server
SIEM Query:
source="web_logs" AND (url_path="/login.php" OR url_path="/auth.php") AND (request_body CONTAINS "' OR" OR request_body CONTAINS "UNION" OR request_body CONTAINS "SELECT *")🔗 References
- https://github.com/nu11secur1ty/CVE-nu11secur1ty/tree/main/vendors/B%26E%20Tracker-by:oretnom23-v1.0
- https://www.sourcecodester.com/php/14893/budget-and-expense-tracker-system-php-free-source-code.html
- https://github.com/nu11secur1ty/CVE-nu11secur1ty/tree/main/vendors/B%26E%20Tracker-by:oretnom23-v1.0
- https://www.sourcecodester.com/php/14893/budget-and-expense-tracker-system-php-free-source-code.html
