CVE-2026-2220: Online Reviewer System SQL Injection Flaw

CVE-2026-2220 Overview

A SQL Injection vulnerability has been identified in Fabian Online Reviewer System version 1.0. The vulnerability exists in the file /system/system/admins/assessments/pretest/btn_functions.php, where improper handling of the difficulty_id parameter allows attackers to inject malicious SQL queries. This vulnerability can be exploited remotely without authentication, potentially allowing unauthorized access to the underlying database, data exfiltration, or manipulation of stored information.

Critical Impact

Remote attackers can exploit this SQL Injection vulnerability to access, modify, or delete sensitive data in the application's database without authentication. The exploit is publicly available, increasing the risk of active exploitation.

Affected Products

• Fabian Online Reviewer System 1.0
• fabian:online_reviewer_system (cpe:2.3:a:fabian:online_reviewer_system:1.0:::::::*)

Discovery Timeline

• 2026-02-09 - CVE CVE-2026-2220 published to NVD
• 2026-02-10 - Last updated in NVD database

Technical Details for CVE-2026-2220

Vulnerability Analysis

This vulnerability is classified under CWE-89 (Improper Neutralization of Special Elements used in an SQL Command) and CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component). The flaw resides in the assessment pretest functionality of the Online Reviewer System, specifically within the btn_functions.php file that handles difficulty level selection.

The application fails to properly sanitize or parameterize user-supplied input in the difficulty_id parameter before incorporating it into SQL queries. This allows an attacker to craft malicious input that modifies the intended query logic, potentially bypassing authentication, extracting sensitive data, or manipulating database records.

Root Cause

The root cause of this vulnerability is insufficient input validation and the lack of parameterized queries (prepared statements) in the PHP code handling the difficulty_id parameter. The application directly concatenates user input into SQL statements without proper escaping or validation, creating a classic SQL Injection attack surface.

Attack Vector

The vulnerability is exploitable over the network, requiring no authentication or user interaction. An attacker can send specially crafted HTTP requests to the vulnerable endpoint at /system/system/admins/assessments/pretest/btn_functions.php with a malicious payload in the difficulty_id parameter.

The attack does not require any privileges, making it particularly dangerous for internet-facing deployments. According to available documentation, the exploit technique has been publicly disclosed, though the immediate exploitation risk remains moderate based on current threat intelligence.

Technical details and proof-of-concept information can be found in the GitHub CVE Issue #20 and VulDB #344937.

Detection Methods for CVE-2026-2220

Indicators of Compromise

• Unusual SQL syntax or error messages in application logs from the /system/system/admins/assessments/pretest/btn_functions.php endpoint
• HTTP requests containing SQL keywords (UNION, SELECT, INSERT, DROP, etc.) in the difficulty_id parameter
• Database query logs showing unexpected queries or extended execution times
• Unexplained changes to database records in assessment-related tables

Detection Strategies

• Deploy Web Application Firewall (WAF) rules to detect and block SQL Injection patterns in HTTP parameters
• Enable database query logging and monitor for anomalous queries originating from the web application
• Implement application-level logging to capture all requests to the vulnerable endpoint
• Use intrusion detection systems (IDS) with SQL Injection signature sets

Monitoring Recommendations

• Monitor web server access logs for requests to btn_functions.php containing suspicious characters or SQL keywords
• Set up alerts for database errors that may indicate SQL Injection attempts (syntax errors, unauthorized table access)
• Review authentication and authorization logs for signs of privilege escalation following potential exploitation

How to Mitigate CVE-2026-2220

Immediate Actions Required

• Restrict network access to the Online Reviewer System to trusted IP addresses only
• Implement Web Application Firewall rules to filter SQL Injection attack patterns
• Consider disabling or removing the pretest assessment functionality if not critical to operations
• Audit database access logs for any signs of prior exploitation

Patch Information

At the time of publication, no official vendor patch has been released for this vulnerability. Organizations should monitor the Code Projects Resource Hub for potential updates. Given the nature of code-projects applications, users may need to implement manual code fixes or consider alternative software solutions.

For additional vulnerability details and community-reported information, refer to VulDB Submission #750020.

Workarounds

• Implement input validation to ensure difficulty_id only accepts expected integer values
• Modify the vulnerable PHP code to use prepared statements with parameterized queries
• Deploy a reverse proxy with SQL Injection filtering capabilities in front of the application
• Limit database user privileges to the minimum required for application functionality

# Example: Restrict access to vulnerable endpoint via .htaccess
# Add to .htaccess in the assessments directory
<Files "btn_functions.php">
    Order Deny,Allow
    Deny from all
    Allow from 192.168.1.0/24
</Files>