CVE-2026-3792: Sales And Inventory System SQLi Vulnerability

CVE-2026-3792 Overview

A SQL Injection vulnerability has been identified in SourceCodester Sales and Inventory System version 1.0. This vulnerability exists in the purchase_invoice.php file within the GET Parameter Handler component. An attacker can exploit this flaw by manipulating the purchaseid parameter, allowing them to inject malicious SQL queries into the backend database. The attack can be performed remotely over the network, and a public exploit has been disclosed, increasing the risk of exploitation.

Critical Impact

Remote attackers with low privileges can exploit this SQL injection vulnerability to access, modify, or delete sensitive data in the Sales and Inventory System database, potentially compromising business-critical financial and inventory records.

Affected Products

• SourceCodester Sales and Inventory System 1.0
• Systems running purchase_invoice.php with unsanitized GET parameter handling
• Web applications utilizing the vulnerable GET Parameter Handler component

Discovery Timeline

• 2026-03-09 - CVE-2026-3792 published to NVD
• 2026-03-09 - Last updated in NVD database

Technical Details for CVE-2026-3792

Vulnerability Analysis

This SQL Injection vulnerability (CWE-89) affects the purchase_invoice.php file in SourceCodester Sales and Inventory System 1.0. The vulnerability is classified as an Injection vulnerability (CWE-74), where user-supplied input through the purchaseid GET parameter is not properly sanitized before being incorporated into SQL queries executed against the backend database.

The vulnerability allows an authenticated attacker with low-level privileges to inject arbitrary SQL statements through the network. Successful exploitation can result in unauthorized access to database contents, data manipulation, and potential data exfiltration. The lack of proper input validation in the GET Parameter Handler creates a direct path for SQL payload injection.

Root Cause

The root cause of this vulnerability is improper input validation and lack of parameterized queries in the purchase_invoice.php file. When processing the purchaseid GET parameter, the application directly concatenates user input into SQL statements without proper sanitization or prepared statement usage. This allows attackers to break out of the intended query structure and inject malicious SQL commands.

Attack Vector

The attack vector is network-based, allowing remote exploitation. An attacker can craft malicious HTTP GET requests containing SQL injection payloads in the purchaseid parameter. The vulnerability requires low-privilege authentication, meaning attackers need valid credentials or access to an authenticated session to exploit this flaw. No user interaction is required beyond the attacker sending the crafted request.

The vulnerability is exploited by appending SQL metacharacters and commands to the purchaseid parameter value. When the application processes this input without proper sanitization, the injected SQL code executes against the database with the privileges of the application's database connection.

Technical details and proof-of-concept information can be found in the GitHub SQL Injection PoC documentation. Additional vulnerability information is available through VulDB #349759.

Detection Methods for CVE-2026-3792

Indicators of Compromise

• Unusual SQL error messages appearing in application logs or HTTP responses related to purchase_invoice.php
• HTTP GET requests to purchase_invoice.php containing SQL metacharacters (single quotes, semicolons, UNION keywords) in the purchaseid parameter
• Database query logs showing unexpected queries originating from the web application context
• Anomalous database access patterns such as bulk data extraction or unauthorized table access

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block SQL injection patterns in GET parameters targeting purchase_invoice.php
• Monitor HTTP access logs for suspicious request patterns containing URL-encoded SQL syntax in the purchaseid parameter
• Deploy database activity monitoring to detect anomalous query patterns or unauthorized data access
• Configure intrusion detection systems (IDS) with signatures for common SQL injection attack strings

Monitoring Recommendations

• Enable detailed logging for all requests to the purchase_invoice.php endpoint
• Set up alerts for database errors that may indicate injection attempts
• Monitor for high volumes of requests to the vulnerable endpoint from single IP addresses
• Review database audit logs regularly for unauthorized SELECT, INSERT, UPDATE, or DELETE operations

How to Mitigate CVE-2026-3792

Immediate Actions Required

• Restrict network access to the Sales and Inventory System to trusted IP ranges only
• Implement input validation and sanitization for all GET parameters, particularly purchaseid
• Deploy a Web Application Firewall (WAF) with SQL injection protection rules as an interim measure
• Review application access logs for evidence of prior exploitation attempts

Patch Information

No official vendor patch has been released at this time. The application is developed by SourceCodester and organizations using this software should monitor the SourceCodester website for security updates. Users are strongly advised to implement the workarounds below and consider code-level remediation by modifying the purchase_invoice.php file to use parameterized queries.

Workarounds

• Implement prepared statements with parameterized queries in the purchase_invoice.php file to prevent SQL injection
• Add server-side input validation to ensure the purchaseid parameter contains only expected numeric values
• Deploy a WAF rule to block requests containing SQL injection patterns in the purchaseid parameter
• Restrict database user privileges used by the web application to limit the impact of successful exploitation

# Example WAF rule configuration (ModSecurity)
SecRule ARGS:purchaseid "@rx [\'\"\;\-\-\=\<\>\(\)]" \
    "id:1001,\
    phase:2,\
    deny,\
    status:403,\
    msg:'SQL Injection attempt detected in purchaseid parameter',\
    logdata:'Matched Data: %{MATCHED_VAR} found within %{MATCHED_VAR_NAME}'"