CVE-2025-11736: Online Examination System SQLi Vulnerability

CVE-2025-11736 Overview

A SQL injection vulnerability has been discovered in itsourcecode Online Examination System version 1.0. The flaw exists in the /index.php file, where improper handling of the Username argument allows attackers to inject malicious SQL statements. This vulnerability can be exploited remotely without authentication, potentially enabling unauthorized access to the underlying database, data exfiltration, and manipulation of examination records.

Critical Impact
Remote attackers can exploit this SQL injection vulnerability to bypass authentication, extract sensitive data including student records and examination results, and potentially compromise the entire examination system database.

Affected Products

itsourcecode Online Examination System 1.0
angeljudesuarez online_examination_system

Discovery Timeline

October 14, 2025 - CVE CVE-2025-11736 published to NVD
October 16, 2025 - Last updated in NVD database

Technical Details for CVE-2025-11736

Vulnerability Analysis

This vulnerability is classified under CWE-89 (SQL Injection) and CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component). The Online Examination System fails to properly sanitize user-supplied input in the Username parameter before incorporating it into SQL queries. This classic SQL injection pattern allows attackers to manipulate the structure of database queries executed by the application.

The vulnerability is particularly concerning in an educational context, where the examination system likely stores sensitive student information, authentication credentials, examination questions, and grade records. The network-accessible nature of the attack vector means any remote attacker can attempt exploitation without requiring prior authentication or local system access.

Root Cause

The root cause of this vulnerability is the lack of proper input validation and parameterized queries in the authentication mechanism. The /index.php file directly concatenates user-supplied input from the Username field into SQL query strings without sanitization. This allows special SQL characters and syntax to be interpreted as part of the query structure rather than as literal data values.

Attack Vector

The attack is conducted remotely via the network by submitting crafted input through the Username field on the login page. An attacker can inject SQL syntax such as single quotes, comment sequences, or UNION-based payloads to manipulate query logic. Common attack patterns include authentication bypass using payloads like ' OR '1'='1 or data extraction through UNION SELECT statements. The exploit has been publicly disclosed and documented, increasing the likelihood of exploitation attempts.

The vulnerability allows for potential:

Authentication bypass to gain unauthorized access
Extraction of sensitive database contents including user credentials
Modification or deletion of examination data
Potential escalation to command execution depending on database configuration

Detection Methods for CVE-2025-11736

Indicators of Compromise

Unusual login attempts containing SQL syntax characters such as single quotes, semicolons, or SQL keywords in log files
Database error messages being triggered or logged during authentication attempts
Unexpected database queries or access patterns in database audit logs
Multiple failed authentication attempts from single IP addresses followed by successful login

Detection Strategies

Implement Web Application Firewall (WAF) rules to detect and block common SQL injection patterns in the Username parameter
Monitor application logs for authentication attempts containing suspicious characters or SQL keywords
Enable database query logging and alert on anomalous query patterns or syntax errors
Deploy intrusion detection systems with signatures for SQL injection attack patterns

Monitoring Recommendations

Enable detailed logging for the /index.php endpoint and authentication events
Configure alerts for database errors related to malformed SQL syntax
Monitor for data exfiltration patterns such as large query result sets or unusual database access times
Review access logs for automated scanning behavior targeting the login functionality

How to Mitigate CVE-2025-11736

Immediate Actions Required

Restrict network access to the Online Examination System to trusted IP ranges or VPN users only
Implement a Web Application Firewall (WAF) with SQL injection protection rules in front of the application
Review database user privileges and ensure the application uses least-privilege database accounts
Enable database audit logging to detect any exploitation attempts

Patch Information

No official vendor patch has been identified in the available CVE data. The vulnerability affects itsourcecode Online Examination System version 1.0 developed by angeljudesuarez. Organizations should monitor the IT Source Code Blog and the GitHub Issue Tracker for updates. Additional technical details are available at VulDB #328220.

Workarounds

Deploy a reverse proxy or WAF to filter malicious SQL injection payloads before they reach the application
Implement custom input validation at the web server level to reject requests containing SQL syntax in the Username field
Consider taking the system offline or restricting access until a proper fix can be implemented
If source code is accessible, manually implement parameterized queries or prepared statements for the authentication function

bash

# Example WAF rule for ModSecurity to block SQL injection in Username parameter
SecRule ARGS:Username "@rx (?i)(\b(select|union|insert|update|delete|drop|alter|exec|execute|xp_|sp_|0x)\b|--|;|\')" \
    "id:100001,phase:2,deny,status:403,log,msg:'SQL Injection attempt blocked in Username parameter'"