CVE-2025-3039: Payroll Management System SQL Injection

CVE-2025-3039 Overview

CVE-2025-3039 is a SQL injection vulnerability in code-projects Payroll Management System 1.0. The flaw resides in the /add_employee.php script, where the lname and fname parameters are passed to a database query without proper sanitization. An authenticated remote attacker can manipulate these parameters to inject arbitrary SQL statements. The exploit has been publicly disclosed, increasing the likelihood of opportunistic abuse. Other parameters in the same endpoint may also be vulnerable. The issue is tracked under [CWE-74] (Improper Neutralization of Special Elements in Output Used by a Downstream Component).

Critical Impact
Remote attackers with low privileges can read, modify, or delete payroll records by injecting SQL through the lname or fname parameters in /add_employee.php.

Affected Products

Fabian Payroll Management System 1.0
code-projects Payroll Management System (distribution source)
Deployments using the vulnerable /add_employee.php endpoint

Discovery Timeline

2025-03-31 - CVE-2025-3039 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-3039

Vulnerability Analysis

The vulnerability is a classic SQL injection in the employee creation workflow of the Payroll Management System. The /add_employee.php script accepts POST parameters including fname (first name) and lname (last name) and concatenates these values directly into a SQL INSERT statement. Because the application does not use parameterized queries or apply input escaping, attacker-controlled syntax breaks out of the string literal and modifies the query structure. The CWE-74 classification reflects improper neutralization of special elements passed to the database engine. According to publicly available EPSS data, the probability of exploitation in the next 30 days is approximately 0.555%.

Root Cause

The root cause is the absence of input validation and prepared statements when handling user-supplied form data. PHP code paths in /add_employee.php concatenate the lname and fname parameters directly into the SQL query string. Special characters such as single quotes, semicolons, and SQL keywords are passed through to the database engine without escaping.

Attack Vector

An attacker submits a crafted HTTP request to /add_employee.php with malicious payloads in the lname or fname fields. The injected SQL executes within the database context used by the web application. Exploitation requires a valid authenticated session because the endpoint sits behind the application's login flow, but no administrative role is needed. Successful injection allows record extraction, modification, or destructive operations such as UNION based data exfiltration and conditional time-based blind injection.

No verified proof-of-concept code is published in the referenced advisories. Technical analysis is available in the GitHub CVE Analysis writeup and the VulDB CVE #302100 entry.

Detection Methods for CVE-2025-3039

Indicators of Compromise

POST requests to /add_employee.php containing SQL metacharacters such as single quotes, double dashes, UNION SELECT, or SLEEP( in fname or lname fields.
Web server logs showing unusually long parameter values or repeated submissions to the employee creation endpoint from a single source.
Database error messages referencing syntax errors near user-supplied tokens appearing in application logs.
Unexpected new rows, deleted records, or altered payroll data in the employee table.

Detection Strategies

Deploy a web application firewall ruleset that inspects POST bodies submitted to /add_employee.php for SQL injection patterns.
Enable verbose query logging on the backend database and alert on syntax errors originating from the web application user.
Correlate authentication events with subsequent anomalous POSTs to the employee endpoint to identify abuse of valid credentials.

Monitoring Recommendations

Forward web server, PHP error, and MySQL/MariaDB logs to a centralized analytics platform for retention and correlation.
Baseline normal request rates and parameter lengths for /add_employee.php and alert on statistical deviations.
Monitor outbound traffic from the web server for signs of data exfiltration following suspicious form submissions.

How to Mitigate CVE-2025-3039

Immediate Actions Required

Restrict network access to the Payroll Management System to trusted internal networks or VPN users until a fix is applied.
Audit recent submissions to /add_employee.php for malicious payloads and review the employee table for unauthorized modifications.
Rotate database credentials used by the application if logs indicate exploitation attempts.

Patch Information

No official vendor patch is referenced in the NVD entry or in the VulDB Entry #302100 at the time of publication. Organizations running this application should track updates on the Code Projects Resource Hub and consider applying source-level fixes by replacing concatenated SQL with prepared statements using PDO or mysqli parameter binding.

Workarounds

Modify /add_employee.php to use parameterized queries with bound parameters for fname, lname, and all other user-supplied fields.
Apply server-side input validation that rejects non-alphabetic characters in name fields before they reach the database layer.
Place the application behind a web application firewall with SQL injection signatures enabled and tuned for the /add_employee.php route.
Run the database account used by the application with the minimum privileges required, removing DROP, ALTER, and cross-database access where possible.

bash

# Example WAF rule (ModSecurity) blocking SQLi patterns on the vulnerable endpoint
SecRule REQUEST_URI "@streq /add_employee.php" \
  "id:1003039,phase:2,deny,status:403,\
   chain,msg:'CVE-2025-3039 SQLi attempt on add_employee.php'"
  SecRule ARGS:fname|ARGS:lname "@rx (?i)(union\s+select|sleep\(|--|';|/\*)" \
    "t:none,t:urlDecodeUni"