CVE-2020-35427
📋 TL;DR
CVE-2020-35427 is a critical SQL injection vulnerability in PHPGurukul Employee Record Management System 1.1 that allows remote attackers to execute arbitrary SQL commands. This enables complete database compromise and authentication bypass, affecting all organizations using this specific version of the software.
💻 Affected Systems
- PHPGurukul Employee Record Management System
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise: attackers gain administrative access, exfiltrate sensitive employee data, modify/delete records, and potentially pivot to other systems.
Likely Case
Authentication bypass leading to unauthorized access to employee records, personal data theft, and privilege escalation within the application.
If Mitigated
Limited impact with proper input validation, parameterized queries, and web application firewall rules blocking SQL injection patterns.
🎯 Exploit Status
Public exploit code is available on Exploit-DB (ID: 49165). The exploit requires minimal technical skill to execute.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown - No official patch released by vendor
Vendor Advisory: No official vendor advisory available
Restart Required: No
Instructions:
1. Immediately upgrade to a newer version if available. 2. If no newer version exists, implement manual code fixes by adding proper input validation and parameterized queries to all SQL statements. 3. Replace vulnerable login/auth components with secure alternatives.
🔧 Temporary Workarounds
Web Application Firewall (WAF) Rules
allImplement WAF rules to block SQL injection patterns in login requests
# Example ModSecurity rule: SecRule ARGS "(?i)(union|select|insert|update|delete|drop|exec)" "id:1001,phase:2,deny,status:403,msg:'SQL Injection Attempt'"
# For naxsi: BasicRule wl:1000 "mz:$ARGS_VAR:username|$ARGS_VAR:password"; Denied
Input Validation Filter
allAdd PHP input validation to sanitize user inputs before SQL processing
<?php
// Example input sanitization
$username = mysqli_real_escape_string($conn, $_POST['username']);
$password = mysqli_real_escape_string($conn, $_POST['password']);
// Better: Use prepared statements
$stmt = $conn->prepare("SELECT * FROM users WHERE username = ? AND password = ?");
$stmt->bind_param("ss", $username, $password);
?>
🧯 If You Can't Patch
- Isolate the system: Place behind VPN, restrict network access to specific IPs only
- Implement strong authentication: Add multi-factor authentication layer before the vulnerable login page
🔍 How to Verify
Check if Vulnerable:
Test login page with SQL injection payloads: ' OR '1'='1 in username/password fields. If login succeeds without valid credentials, system is vulnerable.Check Version:
Check PHP files for version comments or database version table. Look for 'Employee Record Management System Version 1.1' in source code.Verify Fix Applied:
Attempt SQL injection attacks after fixes. Verify prepared statements are used in PHP code and input validation is implemented.📡 Detection & Monitoring
Log Indicators:
- Multiple failed login attempts with SQL keywords (UNION, SELECT, etc.)
- Successful logins from unusual IP addresses
- Database error messages in application logs containing SQL syntax
Network Indicators:
- HTTP POST requests to login.php with SQL payloads in parameters
- Unusual database connection patterns from web server
SIEM Query:
source="web_logs" AND (uri_path="*/login.php" OR uri_path="*/auth.php") AND (http_method="POST") AND (message="*UNION*" OR message="*SELECT*" OR message="*OR '1'='1*")