CVE-2026-5665: Online FIR System SQLi Vulnerability

CVE-2026-5665 Overview

A SQL injection vulnerability has been identified in code-projects Online FIR System 1.0. This vulnerability affects the login functionality within the /Login/checklogin.php file. The manipulation of the email and password arguments allows attackers to inject malicious SQL queries, potentially compromising the entire database backend. The attack can be executed remotely without authentication, and the exploit has been publicly disclosed.

Critical Impact

Unauthenticated attackers can exploit this SQL injection vulnerability remotely to bypass authentication, extract sensitive data from the database, modify records, or potentially achieve further system compromise through database-level attacks.

Affected Products

• code-projects Online FIR System 1.0
• Applications using the vulnerable /Login/checklogin.php component

Discovery Timeline

• 2026-04-06 - CVE-2026-5665 published to NVD
• 2026-04-07 - Last updated in NVD database

Technical Details for CVE-2026-5665

Vulnerability Analysis

This vulnerability stems from improper input validation in the login authentication mechanism of the Online FIR System. The application fails to properly sanitize user-supplied input in the email and password parameters before incorporating them into SQL queries. This allows attackers to manipulate the query logic by injecting SQL syntax, potentially bypassing authentication entirely or extracting sensitive information from the underlying database.

The vulnerability is classified under CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component), which covers injection flaws where untrusted data is sent to an interpreter as part of a command or query.

Root Cause

The root cause of this vulnerability is the lack of proper input sanitization and parameterized queries in the checklogin.php file. The application directly concatenates user input into SQL statements without escaping special characters or using prepared statements. This fundamental coding flaw allows attackers to break out of the intended query structure and inject arbitrary SQL commands.

Attack Vector

The attack is network-based and requires no prior authentication or user interaction. An attacker can craft malicious HTTP POST requests to the /Login/checklogin.php endpoint with specially crafted payloads in the email and password fields. Common attack patterns include:

The vulnerability can be exploited by submitting crafted values in the login form fields. For example, an attacker might submit SQL syntax such as single quotes followed by OR conditions that always evaluate to true, effectively bypassing password verification. More sophisticated attacks could leverage UNION-based injection to extract data from other tables, or time-based blind injection techniques to enumerate database contents character by character.

For detailed technical information on this SQL injection vulnerability, refer to the GitHub SQL Injection Guide and the VulDB #355488 advisory.

Detection Methods for CVE-2026-5665

Indicators of Compromise

• Unusual login activity patterns including multiple rapid authentication attempts with varying SQL syntax in form fields
• Web server access logs showing requests to /Login/checklogin.php with encoded special characters (%27, %22, %3D) in POST data
• Database query logs revealing malformed or unexpected SQL statements with UNION, OR, or comment sequences
• Error messages in application logs indicating SQL syntax errors or database exceptions

Detection Strategies

• Deploy Web Application Firewall (WAF) rules to detect and block common SQL injection patterns in HTTP requests
• Implement logging and alerting for authentication failures with suspicious input patterns
• Monitor database query logs for anomalous query structures or unauthorized data access attempts
• Configure intrusion detection systems to identify SQL injection attack signatures targeting login endpoints

Monitoring Recommendations

• Enable detailed access logging on web servers to capture full request bodies for the /Login/checklogin.php endpoint
• Set up real-time alerts for database errors related to SQL syntax or constraint violations
• Monitor for data exfiltration patterns such as unusually large query result sets or out-of-band DNS requests
• Review authentication logs for successful logins that bypass normal credential validation

How to Mitigate CVE-2026-5665

Immediate Actions Required

• Remove or restrict access to the Online FIR System 1.0 application until the vulnerability is patched
• Implement Web Application Firewall rules to filter SQL injection attempts targeting the login functionality
• Review database access logs for evidence of prior exploitation and potential data compromise
• Consider deploying network-level access controls to limit exposure of the vulnerable endpoint

Patch Information

No official vendor patch has been identified for this vulnerability at the time of publication. Organizations using code-projects Online FIR System 1.0 should contact the vendor through Code Projects Resources for remediation guidance. As this is an open-source educational project, users may need to implement their own fixes or migrate to an alternative solution.

Additional vulnerability details and threat intelligence are available at VulDB #355488 CTI.

Workarounds

• Modify the checklogin.php source code to use prepared statements with parameterized queries instead of string concatenation
• Implement server-side input validation to reject email and password inputs containing SQL metacharacters
• Deploy a reverse proxy or WAF with SQL injection filtering capabilities in front of the application
• Restrict network access to the application to trusted IP ranges or internal networks only

# Example: Apache mod_security rule to block SQL injection attempts
SecRule ARGS "@detectSQLi" "id:1001,phase:2,deny,status:403,msg:'SQL Injection Attack Detected'"

# Example: Restrict access to login endpoint by IP
<Location "/Login/checklogin.php">
    Require ip 10.0.0.0/8 192.168.0.0/16
</Location>