CVE-2026-2173: Fabian Online Examination System SQLi

CVE-2026-2173 Overview

A SQL Injection vulnerability has been identified in the Fabian Online Examination System version 1.0. This vulnerability affects the login.php file, where improper handling of the username and password parameters allows attackers to inject malicious SQL queries. The flaw enables remote attackers to manipulate database queries without requiring authentication, potentially leading to unauthorized access to sensitive examination data, user credentials, and administrative functions.

Critical Impact
Remote attackers can exploit this SQL injection vulnerability to bypass authentication, extract sensitive data from the database, and potentially gain unauthorized administrative access to the Online Examination System.

Affected Products

Fabian Online Examination System 1.0

Discovery Timeline

2026-02-08 - CVE CVE-2026-2173 published to NVD
2026-02-11 - Last updated in NVD database

Technical Details for CVE-2026-2173

Vulnerability Analysis

This SQL Injection vulnerability (CWE-89) resides in the authentication mechanism of the Online Examination System. The login.php file fails to properly sanitize user-supplied input for the username and password parameters before incorporating them into SQL queries. This allows attackers to inject arbitrary SQL statements that are executed by the database server.

The vulnerability also falls under CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component), indicating that the application fails to neutralize special characters that have syntactic meaning in SQL contexts.

Root Cause

The root cause of this vulnerability is the direct concatenation of user input into SQL queries without proper sanitization or the use of parameterized queries. When user-supplied data is passed to the username and password fields in login.php, the application constructs SQL statements by embedding this input directly, creating an injection point that attackers can exploit to modify query logic.

Attack Vector

The attack can be initiated remotely over the network without requiring any authentication or user interaction. An attacker can craft malicious input containing SQL metacharacters and injection payloads in the login form fields. Common attack scenarios include:

Authentication Bypass: Injecting payloads like ' OR '1'='1 to bypass login validation
Data Exfiltration: Using UNION-based or blind SQL injection techniques to extract database contents
Privilege Escalation: Manipulating queries to access or modify administrative accounts

The vulnerability is accessible via the network attack vector, requires low complexity to exploit, and needs no privileges or user interaction, making it particularly dangerous for internet-facing deployments.

Detection Methods for CVE-2026-2173

Indicators of Compromise

Unusual login activity or successful authentication from unexpected IP addresses
Database logs showing malformed SQL queries or syntax errors in authentication-related queries
Presence of SQL keywords and special characters (UNION, SELECT, OR, --, ') in web server access logs for login.php
Unexpected database enumeration or data access patterns

Detection Strategies

Implement Web Application Firewall (WAF) rules to detect SQL injection patterns in login requests
Monitor application logs for repeated failed login attempts with unusual character patterns
Configure database query logging and alert on queries containing SQL injection signatures
Deploy intrusion detection systems with SQL injection attack signatures enabled

Monitoring Recommendations

Enable detailed logging for all authentication endpoints, particularly login.php
Set up real-time alerting for database query anomalies and syntax errors
Monitor for unauthorized data access or bulk data retrieval patterns
Review access logs regularly for suspicious parameter values in login requests

How to Mitigate CVE-2026-2173

Immediate Actions Required

Restrict network access to the Online Examination System to trusted IP ranges only
Implement a Web Application Firewall with SQL injection protection enabled
Consider taking the application offline if it processes sensitive examination data until the vulnerability is addressed
Audit database logs for evidence of prior exploitation attempts

Patch Information

No official vendor patch information is currently available for this vulnerability. Organizations using Fabian Online Examination System 1.0 should contact the vendor for remediation guidance or consider implementing the workarounds below. For additional technical details, refer to the VulDB entry for this vulnerability.

Workarounds

Implement prepared statements or parameterized queries in the login.php file to prevent SQL injection
Add input validation to reject special SQL characters in username and password fields
Deploy a Web Application Firewall (WAF) configured to block SQL injection attempts
Implement rate limiting on the login endpoint to slow down automated attack attempts
Apply the principle of least privilege to the database user account used by the application

bash

# Example: Block access to login.php from untrusted networks using iptables
# Replace 10.0.0.0/8 with your trusted network range
iptables -A INPUT -p tcp --dport 80 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP

# Example: Apache mod_security rule to detect SQL injection in POST parameters
# Add to your ModSecurity configuration
SecRule ARGS "@detectSQLi" "id:1001,deny,status:403,msg:'SQL Injection Attempt Detected'"