CVE-2021-26765
📋 TL;DR
CVE-2021-26765 is a critical SQL injection vulnerability in PHPGurukul Student Record System 4.0 that allows remote attackers to execute arbitrary SQL commands via the sid parameter in edit-sub.php. This affects all organizations using the vulnerable version of this student management software, potentially exposing sensitive student data and system control.
💻 Affected Systems
- PHPGurukul Student Record System
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete database compromise leading to data theft, data manipulation, authentication bypass, and potential remote code execution via database functions.
Likely Case
Unauthorized access to sensitive student records (grades, personal information), administrative data theft, and potential system takeover.
If Mitigated
Limited impact with proper input validation and parameterized queries preventing SQL injection.
🎯 Exploit Status
Exploit code is publicly available on Packet Storm and GitHub. The attack requires minimal technical skill.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: No official vendor advisory found
Restart Required: No
Instructions:
No official patch available. Consider migrating to alternative software or implementing custom fixes with parameterized queries.
🔧 Temporary Workarounds
Input Validation and Sanitization
allImplement server-side validation and sanitization of the sid parameter in edit-sub.php
Modify edit-sub.php to use prepared statements: $stmt = $conn->prepare('SELECT * FROM students WHERE id = ?'); $stmt->bind_param('i', $_GET['sid']);
Web Application Firewall (WAF)
allDeploy WAF rules to block SQL injection patterns in sid parameter
Add WAF rule: Detect and block SQL injection patterns in GET/POST parameters
🧯 If You Can't Patch
- Isolate the system from internet access and restrict to internal network only
- Implement strict network segmentation and monitor all database queries from the application
🔍 How to Verify
Check if Vulnerable:
Test the edit-sub.php endpoint with SQL injection payloads in sid parameter: edit-sub.php?sid=1' OR '1'='1Check Version:
Check PHPGurukul version in admin panel or system configuration filesVerify Fix Applied:
Test with same payloads after fix - should return error or no data instead of executing SQL📡 Detection & Monitoring
Log Indicators:
- Unusual SQL queries in database logs
- Multiple failed login attempts after SQL injection
- Unexpected database schema changes
Network Indicators:
- HTTP requests to edit-sub.php with SQL keywords in parameters
- Unusual database connection patterns from web server
SIEM Query:
source=web_logs AND uri="*edit-sub.php*" AND (param="*UNION*" OR param="*SELECT*" OR param="*OR '1'='1*")🔗 References
- https://github.com/BigTiger2020/Student-Record-System-/blob/main/README.md
- https://packetstormsecurity.com/files/161237/Student-Record-System-4.0-SQL-Injection.html
- https://phpgurukul.com/
- https://phpgurukul.com/wp-content/uploads/2019/05/schoolmanagement.zip
- https://github.com/BigTiger2020/Student-Record-System-/blob/main/README.md
- https://packetstormsecurity.com/files/161237/Student-Record-System-4.0-SQL-Injection.html
- https://phpgurukul.com/
- https://phpgurukul.com/wp-content/uploads/2019/05/schoolmanagement.zip
