CVE-2026-39110: Apartment Visitors Management SQLi Flaw

CVE-2026-39110 Overview

A SQL Injection vulnerability exists in Apartment Visitors Management System V1.1, specifically in the contactno parameter of the forgot password page (forgot-password.php). This vulnerability allows an unauthenticated attacker to manipulate backend SQL queries during the authentication process and retrieve sensitive database contents.

Critical Impact

Unauthenticated attackers can exploit this SQL injection to bypass authentication mechanisms and extract sensitive data from the database, including user credentials, personal information, and administrative data.

Affected Products

• Apartment Visitors Management System V1.1
• PHP Gurukul Apartment Visitors Management System (PHP/MySQL)

Discovery Timeline

• 2026-04-20 - CVE-2026-39110 published to NVD
• 2026-04-20 - Last updated in NVD database

Technical Details for CVE-2026-39110

Vulnerability Analysis

This SQL Injection vulnerability (CWE-89) affects the password recovery functionality of the Apartment Visitors Management System. The vulnerable endpoint forgot-password.php fails to properly sanitize the contactno parameter before incorporating it into SQL queries. When a user submits their contact number to recover their password, the application directly concatenates the input into a database query without proper parameterization or input validation.

The network-accessible nature of this vulnerability means attackers can exploit it remotely without any authentication or user interaction. The primary impact is on confidentiality, allowing attackers to extract sensitive database contents, though limited integrity impact exists through potential data manipulation.

Root Cause

The root cause is improper input validation and the use of dynamic SQL query construction. The contactno parameter is directly embedded into SQL statements without proper sanitization, prepared statements, or parameterized queries. This classic SQL injection pattern occurs when user-controlled input is trusted and concatenated directly into database queries.

Attack Vector

The attack vector is network-based and requires no authentication or privileges. An attacker can submit specially crafted input through the forgot password form, injecting malicious SQL syntax into the contactno field. This allows the attacker to modify the intended SQL query logic, potentially enabling:

• Database enumeration and data extraction
• Authentication bypass
• Retrieval of user credentials and personal information
• Access to administrative records

The vulnerability can be exploited by injecting SQL payloads into the contact number field. Techniques such as UNION-based injection, boolean-based blind injection, or time-based blind injection could be used to extract database contents. Technical details and proof-of-concept information are available in the GitHub CVE Repository.

Detection Methods for CVE-2026-39110

Indicators of Compromise

• Unusual or malformed requests to forgot-password.php containing SQL syntax characters such as single quotes, double dashes, or UNION keywords
• Multiple failed or anomalous password recovery attempts from the same IP address
• Database query errors appearing in application logs related to the password recovery function
• Unexpected data extraction patterns or large result sets from authentication-related tables

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block SQL injection patterns in the contactno parameter
• Monitor HTTP request logs for suspicious patterns targeting forgot-password.php with encoded or obfuscated SQL payloads
• Enable database query logging and alert on queries containing unexpected SQL keywords or syntax anomalies
• Deploy intrusion detection signatures for common SQL injection attack patterns

Monitoring Recommendations

• Configure real-time alerting for any SQL error messages generated by the application
• Monitor for unusual database access patterns, especially bulk data retrieval from user tables
• Track and analyze traffic patterns to the password recovery endpoint for volumetric anomalies
• Review authentication and access logs for signs of credential compromise following exploitation attempts

How to Mitigate CVE-2026-39110

Immediate Actions Required

• Restrict or disable access to the forgot-password.php endpoint until a patch is applied
• Implement a Web Application Firewall (WAF) rule to filter SQL injection attempts targeting the contactno parameter
• Review database logs for evidence of past exploitation and rotate any potentially compromised credentials
• Consider temporarily disabling the password recovery feature if it cannot be adequately protected

Patch Information

As of the last modification date, no official vendor patch has been confirmed in the available CVE data. System administrators should monitor the PHP Gurukul project page for security updates. If no patch is available, consider implementing code-level fixes using prepared statements and parameterized queries for all database interactions.

Workarounds

• Implement server-side input validation to allow only numeric characters in the contactno field
• Deploy parameterized queries or prepared statements in the forgot-password.php file to prevent SQL injection
• Use a Web Application Firewall to filter and block malicious input patterns
• Restrict network access to the application to trusted IP ranges where possible
• Consider implementing rate limiting on the password recovery endpoint to slow automated exploitation attempts

# Example WAF rule to block SQL injection in contactno parameter
# ModSecurity rule example
SecRule ARGS:contactno "@rx (?i)(union|select|insert|update|delete|drop|exec|xp_)" \
    "id:100001,phase:2,deny,status:403,log,msg:'SQL Injection attempt blocked in contactno parameter'"