CVE-2026-3754: Sales And Inventory System SQLi Vulnerability

CVE-2026-3754 Overview

A SQL injection vulnerability has been identified in SourceCodester Sales and Inventory System version 1.0. This vulnerability affects the /add_stock.php file, where improper handling of the cost parameter allows attackers to inject malicious SQL statements. The attack can be initiated remotely by authenticated users, potentially leading to unauthorized data access, modification, or deletion within the underlying database.

Critical Impact

Remote attackers can exploit this SQL injection vulnerability to manipulate database queries, potentially accessing sensitive business data including sales records, inventory information, and customer details stored in the application's database.

Affected Products

• SourceCodester Sales and Inventory System 1.0
• Ahsanriaz26gmailcom Sales And Inventory System

Discovery Timeline

• 2026-03-08 - CVE CVE-2026-3754 published to NVD
• 2026-03-09 - Last updated in NVD database

Technical Details for CVE-2026-3754

Vulnerability Analysis

This SQL injection vulnerability exists in the stock management functionality of the Sales and Inventory System. The application fails to properly sanitize user-supplied input in the cost parameter before incorporating it into SQL queries. When users submit stock information through the /add_stock.php endpoint, the application directly concatenates the cost parameter value into database queries without adequate input validation or parameterized query usage.

The vulnerability is classified under CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component), which encompasses injection flaws. An authenticated attacker with low privileges can exploit this flaw to execute arbitrary SQL commands against the backend database.

Root Cause

The root cause of this vulnerability is improper input validation and the absence of parameterized queries (prepared statements) in the /add_stock.php file. The application directly incorporates user-controlled data from the cost parameter into SQL statements, allowing attackers to break out of the intended query structure and inject malicious SQL code. This is a classic example of failing to follow secure coding practices for database interactions.

Attack Vector

The attack vector is network-based, requiring the attacker to have low-level privileges (authentication) to access the vulnerable endpoint. The exploitation process involves:

1. The attacker authenticates to the Sales and Inventory System
2. The attacker navigates to the stock management functionality
3. A crafted payload containing SQL injection syntax is submitted via the cost parameter to /add_stock.php
4. The malicious SQL is executed against the database, allowing data extraction, modification, or deletion

The vulnerability has been publicly disclosed with a proof-of-concept available. For technical details on the exploitation technique, refer to the GitHub SQL Injection PoC.

Detection Methods for CVE-2026-3754

Indicators of Compromise

• Unusual or malformed requests to /add_stock.php containing SQL syntax characters such as single quotes, double dashes, or UNION keywords in the cost parameter
• Database errors or unexpected query results logged by the application server
• Abnormal database activity including unauthorized SELECT statements or data exfiltration patterns
• Web application firewall alerts for SQL injection patterns targeting the affected endpoint

Detection Strategies

• Deploy web application firewall (WAF) rules to detect and block SQL injection attempts targeting the /add_stock.php endpoint
• Implement application-level logging to capture all requests to the vulnerable endpoint with full parameter values
• Configure database auditing to monitor for suspicious query patterns, especially those involving UNION-based or error-based injection techniques
• Use intrusion detection systems (IDS) with signatures for common SQL injection payloads

Monitoring Recommendations

• Monitor web server access logs for requests to /add_stock.php containing suspicious characters or encoding
• Set up alerts for database query failures or unexpected query execution patterns
• Review authentication logs for compromised accounts that may be used to access the vulnerable functionality
• Implement real-time monitoring of database operations for anomalous data access patterns

How to Mitigate CVE-2026-3754

Immediate Actions Required

• Restrict access to the /add_stock.php endpoint to trusted users only until a patch is available
• Implement input validation at the web application firewall level to block SQL injection payloads
• Consider taking the affected application offline if it handles sensitive data and cannot be adequately protected
• Review access logs to determine if the vulnerability has already been exploited

Patch Information

No official vendor patch information is currently available for this vulnerability. The affected software is distributed through SourceCodester, and users should monitor the SourceCodester Security Resources for updates. Additional vulnerability details can be found at VulDB #349732.

Workarounds

• Modify the source code to implement parameterized queries (prepared statements) for all database operations in /add_stock.php
• Add server-side input validation to sanitize the cost parameter, ensuring only numeric values are accepted
• Deploy a web application firewall with SQL injection protection rules enabled for the affected endpoint
• Implement the principle of least privilege for database accounts used by the application to limit the impact of successful exploitation

# Configuration example - Apache ModSecurity WAF rule to block SQL injection
SecRule ARGS:cost "@detectSQLi" \
    "id:100001,\
    phase:2,\
    deny,\
    status:403,\
    log,\
    msg:'SQL Injection attempt detected in cost parameter - CVE-2026-3754',\
    tag:'attack-sqli'"