CVE-2025-4773: PHPGurukul Course Registration SQLi Flaw

CVE-2025-4773 Overview

A SQL injection vulnerability has been identified in PHPGurukul Online Course Registration version 3.1. This vulnerability exists in the /admin/level.php file where improper handling of the level parameter allows attackers to inject malicious SQL statements. The vulnerability enables remote attackers to manipulate database queries without authentication, potentially leading to unauthorized data access, modification, or deletion.

Critical Impact

Remote attackers can exploit this SQL injection flaw to bypass authentication, extract sensitive data from the database, modify records, or potentially gain further system access through the compromised web application.

Affected Products

• PHPGurukul Online Course Registration version 3.1
• Web applications using the vulnerable /admin/level.php endpoint

Discovery Timeline

• 2025-05-16 - CVE-2025-4773 published to NVD
• 2025-05-21 - Last updated in NVD database

Technical Details for CVE-2025-4773

Vulnerability Analysis

This vulnerability is classified as SQL Injection (CWE-89) and falls under the broader category of Injection vulnerabilities (CWE-74). The flaw resides in the administrative functionality of the Online Course Registration application, specifically within the level.php script located in the /admin/ directory.

The vulnerable endpoint fails to properly sanitize or parameterize user-supplied input in the level parameter before incorporating it into SQL queries. This allows attackers to craft malicious input that modifies the intended SQL query logic, enabling them to execute arbitrary database commands.

Since the attack vector is network-based and requires no authentication or user interaction, any attacker with network access to the vulnerable application can exploit this flaw remotely. The public disclosure of exploit details increases the risk of active exploitation.

Root Cause

The root cause of this vulnerability is insufficient input validation and the absence of parameterized queries (prepared statements) in the level.php file. When user input from the level parameter is directly concatenated into SQL statements without proper sanitization or escaping, attackers can break out of the intended query structure and inject their own SQL commands.

Attack Vector

The vulnerability can be exploited remotely over the network. An attacker can send specially crafted HTTP requests to the /admin/level.php endpoint with malicious SQL payloads in the level parameter. The attack does not require authentication, making it accessible to any remote attacker who can reach the vulnerable application.

Common exploitation techniques for this SQL injection include:

• Union-based injection: Extracting data from other database tables by appending UNION SELECT statements
• Boolean-based blind injection: Inferring database contents through true/false responses
• Time-based blind injection: Using database sleep functions to exfiltrate data character by character
• Error-based injection: Leveraging database error messages to extract information

For detailed technical information about this vulnerability, refer to the GitHub CVE Issue Discussion and the VulDB CVE Analysis #309074.

Detection Methods for CVE-2025-4773

Indicators of Compromise

• Unusual or malformed requests to /admin/level.php containing SQL syntax characters such as single quotes, double dashes, or UNION keywords
• Database error messages appearing in web application responses or logs
• Unexplained database queries or modifications in database audit logs
• Anomalous access patterns to administrative endpoints from external IP addresses

Detection Strategies

• Deploy Web Application Firewall (WAF) rules to detect and block common SQL injection patterns targeting the level parameter
• Implement application-level logging for all requests to /admin/level.php and monitor for suspicious input patterns
• Enable database query logging and alert on queries containing injection signatures or syntax errors
• Use intrusion detection systems (IDS) with signatures for SQL injection attack patterns

Monitoring Recommendations

• Monitor web server access logs for requests to /admin/level.php with unusual query string parameters
• Set up alerts for database errors that may indicate failed injection attempts
• Track failed authentication attempts and access to administrative endpoints from unknown sources
• Implement real-time monitoring for data exfiltration patterns from the application database

How to Mitigate CVE-2025-4773

Immediate Actions Required

• Remove or restrict access to the /admin/level.php endpoint until a patch is applied
• Implement IP-based access controls to limit administrative interface access to trusted networks only
• Deploy a Web Application Firewall (WAF) with SQL injection protection rules in blocking mode
• Review database logs for signs of prior exploitation and potential data compromise

Patch Information

At the time of publication, no official patch has been released by PHPGurukul for this vulnerability. Organizations should monitor the PHP Gurukul Security Resource for security updates. In the absence of an official patch, implement the workarounds listed below and consider replacing the vulnerable component with a more secure alternative.

Workarounds

• Apply input validation to the level parameter by implementing a whitelist of allowed values or strict type checking
• Modify the vulnerable code to use prepared statements with parameterized queries instead of string concatenation
• Restrict access to the /admin/ directory using .htaccess rules or server configuration to allow only authorized IP addresses
• Consider placing the application behind a reverse proxy with SQL injection filtering capabilities

# Apache .htaccess example to restrict admin access by IP
<Directory "/var/www/html/admin">
    Order Deny,Allow
    Deny from all
    Allow from 192.168.1.0/24
    Allow from 10.0.0.0/8
</Directory>