CVE-2025-7131: Payroll Management System SQL Injection

CVE-2025-7131 Overview

A critical SQL injection vulnerability has been identified in Campcodes Payroll Management System version 1.0. The vulnerability exists in the /ajax.php?action=save_employee_attendance endpoint, where the employee_id parameter is not properly sanitized before being used in SQL queries. This allows unauthenticated remote attackers to inject malicious SQL commands, potentially compromising the entire database backend.

Critical Impact

Unauthenticated attackers can exploit this SQL injection vulnerability remotely to extract sensitive payroll data, modify employee records, or potentially gain unauthorized access to the underlying database system.

Affected Products

• Campcodes Payroll Management System 1.0

Discovery Timeline

• 2025-07-07 - CVE-2025-7131 published to NVD
• 2025-07-08 - Last updated in NVD database

Technical Details for CVE-2025-7131

Vulnerability Analysis

This SQL injection vulnerability stems from improper input validation in the Campcodes Payroll Management System. The affected endpoint /ajax.php?action=save_employee_attendance accepts user-supplied input through the employee_id parameter without adequate sanitization or parameterized query implementation. When processing attendance records, the application directly concatenates user input into SQL queries, creating a classic injection point.

The attack is network-accessible without requiring authentication, meaning any remote attacker who can reach the application can attempt exploitation. Once exploited, attackers could read, modify, or delete database contents including sensitive payroll information such as employee salaries, bank account details, and personal identification data.

Root Cause

The root cause is classified under CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component), commonly known as injection vulnerabilities. The application fails to properly sanitize the employee_id parameter before incorporating it into SQL statements. This lack of input validation allows special SQL characters and commands to be interpreted by the database engine rather than being treated as data.

Attack Vector

The attack vector is network-based, allowing remote exploitation. An attacker can craft malicious HTTP requests to the vulnerable AJAX endpoint, injecting SQL syntax through the employee_id parameter. The exploit has been publicly disclosed, increasing the risk of widespread exploitation attempts.

The attack flow involves sending a specially crafted POST request to /ajax.php?action=save_employee_attendance with SQL injection payloads in the employee_id field. Common techniques include UNION-based injection for data extraction, time-based blind injection for data enumeration, and stacked queries for more advanced attacks depending on the database configuration.

For technical details and proof-of-concept information, refer to the GitHub Issue Discussion and VulDB #315043.

Detection Methods for CVE-2025-7131

Indicators of Compromise

• Unusual HTTP requests to /ajax.php?action=save_employee_attendance containing SQL syntax characters such as single quotes, UNION statements, or semicolons
• Database error messages in application logs indicating malformed SQL queries
• Unexpected database queries or data access patterns in SQL audit logs
• Large volumes of requests to the attendance endpoint from single IP addresses

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect SQL injection patterns in the employee_id parameter
• Monitor application logs for HTTP 500 errors or database-related exceptions from the affected endpoint
• Deploy intrusion detection signatures for common SQL injection payloads targeting PHP applications
• Review access logs for suspicious patterns targeting /ajax.php with unusual parameter values

Monitoring Recommendations

• Enable detailed logging for all requests to the /ajax.php endpoint
• Configure database audit logging to track query execution and data access patterns
• Set up alerts for failed database authentication attempts or privilege escalation queries
• Monitor for data exfiltration patterns such as large result sets or systematic data enumeration

How to Mitigate CVE-2025-7131

Immediate Actions Required

• Restrict network access to the Payroll Management System to trusted IP ranges only
• Implement a Web Application Firewall with SQL injection detection rules
• Consider temporarily disabling the affected attendance functionality until a patch is available
• Audit database logs for signs of prior exploitation attempts

Patch Information

At the time of publication, no official patch has been released by Campcodes for this vulnerability. Organizations using the affected software should monitor the Campcodes website for security updates and apply patches immediately when available. Consider contacting the vendor directly for remediation guidance.

Workarounds

• Deploy input validation at the web server level using ModSecurity or similar WAF with SQL injection rule sets
• Implement network segmentation to isolate the Payroll Management System from untrusted networks
• Add application-level input sanitization by modifying the ajax.php file to use parameterized queries or prepared statements
• Restrict database user privileges to minimum required permissions to limit the impact of successful exploitation

# Example ModSecurity rule to block SQL injection in employee_id parameter
SecRule ARGS:employee_id "@detectSQLi" \
    "id:1001,\
    phase:2,\
    deny,\
    status:403,\
    log,\
    msg:'SQL Injection attempt detected in employee_id parameter',\
    tag:'CVE-2025-7131'"