CVE-2026-3790: Sales And Inventory System SQLi Vulnerability

CVE-2026-3790 Overview

A SQL Injection vulnerability has been identified in SourceCodester Sales and Inventory System 1.0. This vulnerability affects the check_supplier_details.php file within the POST Parameter Handler component. An attacker can exploit this flaw by manipulating the stock_name1 argument to inject malicious SQL commands. The attack can be executed remotely over the network, and a proof-of-concept exploit has been publicly disclosed.

Critical Impact

Remote attackers with low-level privileges can exploit this SQL Injection vulnerability to access, modify, or delete database records, potentially compromising sensitive business data including supplier information, sales records, and inventory data.

Affected Products

• SourceCodester Sales and Inventory System 1.0
• ahsanriaz26gmailcom sales_and_inventory_system

Discovery Timeline

• 2026-03-09 - CVE-2026-3790 published to NVD
• 2026-03-09 - Last updated in NVD database

Technical Details for CVE-2026-3790

Vulnerability Analysis

This SQL Injection vulnerability (CWE-89) exists due to improper neutralization of special elements used in SQL commands within the check_supplier_details.php file. The vulnerability falls under the broader category of Injection (CWE-74), where user-supplied input is not properly sanitized before being incorporated into SQL queries. The flaw allows authenticated attackers with low privileges to execute arbitrary SQL statements against the backend database.

The attack requires network access and can be performed without user interaction. An attacker can leverage this vulnerability to extract sensitive information from the database, modify existing records, or potentially escalate their access within the application.

Root Cause

The root cause of this vulnerability lies in insufficient input validation and lack of parameterized queries in the check_supplier_details.php file. The stock_name1 POST parameter is directly concatenated into SQL queries without proper sanitization or the use of prepared statements. This allows attackers to break out of the intended query structure and inject additional SQL commands that will be executed by the database server.

Attack Vector

The vulnerability is exploitable via the network attack vector through the POST Parameter Handler. An attacker with low-level authentication can craft malicious HTTP POST requests containing SQL injection payloads in the stock_name1 parameter. When the check_supplier_details.php script processes this request, the injected SQL commands are executed with the privileges of the database user configured for the application.

The exploitation is straightforward with low attack complexity, requiring no user interaction. An attacker can probe the injection point to determine database structure, then extract data, manipulate records, or potentially achieve further system compromise depending on database configuration and privileges.

For technical details on exploitation, refer to the GitHub SQLi PoC documentation.

Detection Methods for CVE-2026-3790

Indicators of Compromise

• Unusual or malformed HTTP POST requests to check_supplier_details.php containing SQL syntax characters such as single quotes, double dashes, UNION statements, or SELECT keywords in the stock_name1 parameter
• Database error messages in application logs indicating SQL syntax errors or unexpected query behavior
• Anomalous database query patterns including UNION-based attacks, time-based blind injection attempts, or excessive data extraction queries
• Unauthorized access patterns showing data retrieval beyond normal application usage for supplier details

Detection Strategies

• Deploy Web Application Firewall (WAF) rules to detect and block SQL injection patterns in POST parameters targeting check_supplier_details.php
• Implement application-level logging to capture all requests to the vulnerable endpoint with full parameter inspection
• Configure database activity monitoring to alert on suspicious query patterns including UNION injections, stacked queries, or uncommon data access
• Enable intrusion detection system (IDS) signatures for SQL injection attack patterns in HTTP traffic

Monitoring Recommendations

• Monitor HTTP access logs for requests to check_supplier_details.php with abnormal stock_name1 parameter lengths or suspicious content
• Set up alerts for database errors correlated with requests to the Sales and Inventory System application
• Review authentication logs for patterns indicating privilege escalation attempts following potential SQL injection exploitation
• Implement real-time alerting for any database schema enumeration queries or bulk data extraction operations

How to Mitigate CVE-2026-3790

Immediate Actions Required

• Restrict network access to the Sales and Inventory System to trusted IP addresses or internal networks only until a patch is applied
• Implement a Web Application Firewall rule to block SQL injection attempts targeting the check_supplier_details.php endpoint
• Review database user privileges and apply principle of least privilege to limit potential impact from SQL injection
• Enable detailed logging for all requests to the affected endpoint for forensic analysis

Patch Information

No vendor patch information is currently available for this vulnerability. The affected software is distributed through SourceCodester, a repository of open-source code samples. Users should monitor the project for updates or consider implementing manual fixes to address the SQL injection vulnerability.

For additional vulnerability details, consult the VulDB entry which tracks this issue.

Workarounds

• Implement parameterized queries or prepared statements in the check_supplier_details.php file to properly escape user input
• Add input validation to the stock_name1 parameter to reject requests containing SQL metacharacters or syntax
• Deploy a WAF with SQL injection protection rules in blocking mode for the affected endpoint
• Consider disabling or removing the check_supplier_details.php functionality if it is not critical to business operations

# Example: Apache .htaccess rule to restrict access to vulnerable file
<Files "check_supplier_details.php">
    Order Deny,Allow
    Deny from all
    Allow from 192.168.1.0/24
</Files>