CVE-2026-3756: Sales And Inventory System SQLi Vulnerability

CVE-2026-3756 Overview

A SQL injection vulnerability has been identified in SourceCodester Sales and Inventory System up to version 1.0. The vulnerability exists in the /check_item_details.php file, where improper handling of the stock_name1 parameter allows attackers to inject malicious SQL queries. This flaw can be exploited remotely by authenticated users to manipulate database queries, potentially leading to unauthorized data access, modification, or deletion.

Critical Impact

Attackers can exploit this SQL injection vulnerability to extract sensitive inventory and sales data, modify database records, or potentially escalate access within the affected system.

Affected Products

• SourceCodester Sales and Inventory System version 1.0
• ahsanriaz26gmailcom sales_and_inventory_system

Discovery Timeline

• 2026-03-08 - CVE-2026-3756 published to NVD
• 2026-03-09 - Last updated in NVD database

Technical Details for CVE-2026-3756

Vulnerability Analysis

This SQL injection vulnerability stems from insufficient input validation in the check_item_details.php endpoint. When a user submits a request containing the stock_name1 parameter, the application fails to properly sanitize or parameterize the input before incorporating it into SQL queries. This allows an attacker to craft malicious input that modifies the intended query logic.

The vulnerability is classified under CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component), which encompasses injection flaws where untrusted data is concatenated with code or queries. The attack can be initiated remotely over the network and requires low-privilege authentication to exploit.

A proof-of-concept exploit has been publicly disclosed, making this vulnerability accessible to a wider range of potential attackers. Organizations using this inventory management system should prioritize remediation efforts.

Root Cause

The root cause of this vulnerability is the failure to implement proper input sanitization and parameterized queries in the check_item_details.php file. The stock_name1 parameter is directly concatenated into SQL statements without escaping special characters or using prepared statements, allowing attackers to break out of the intended query context and execute arbitrary SQL commands.

Attack Vector

The attack vector is network-based, requiring the attacker to send specially crafted HTTP requests to the vulnerable endpoint. The exploitation flow typically follows this pattern:

1. An authenticated attacker identifies the vulnerable /check_item_details.php endpoint
2. The attacker crafts a malicious value for the stock_name1 parameter containing SQL injection payloads
3. The application processes the request and incorporates the malicious input directly into the SQL query
4. The database executes the modified query, potentially returning unauthorized data or performing unintended operations

The vulnerability allows attackers to extract database contents, bypass authentication mechanisms, modify or delete records, and potentially gain further access to the underlying system depending on database permissions. Technical details and a proof-of-concept are available in the GitHub SQL Injection PoC repository.

Detection Methods for CVE-2026-3756

Indicators of Compromise

• Unusual or malformed requests to /check_item_details.php containing SQL syntax characters such as single quotes, double dashes, or UNION statements
• Database error messages appearing in application logs or HTTP responses indicating SQL syntax errors
• Unexpected database query patterns showing data extraction from multiple tables
• Authentication logs showing successful access followed by anomalous data retrieval operations

Detection Strategies

• Deploy Web Application Firewall (WAF) rules to detect and block SQL injection patterns in the stock_name1 parameter
• Implement application-level logging to capture all requests to check_item_details.php and flag those containing suspicious characters
• Configure database activity monitoring to alert on unusual query patterns or access to sensitive tables
• Use intrusion detection systems (IDS) with signatures for common SQL injection payloads

Monitoring Recommendations

• Enable verbose logging for the web application and database to capture detailed request information
• Set up alerts for database errors that may indicate injection attempts
• Monitor for unusual data exfiltration patterns from the inventory system database
• Review access logs regularly for requests containing encoded or obfuscated SQL injection payloads

How to Mitigate CVE-2026-3756

Immediate Actions Required

• Restrict access to the Sales and Inventory System to trusted internal networks only until patching is complete
• Implement input validation on the stock_name1 parameter to allow only alphanumeric characters
• Deploy WAF rules to block requests containing SQL injection patterns
• Review database user permissions and apply the principle of least privilege to limit potential damage from exploitation

Patch Information

No official vendor patch has been identified for this vulnerability. Users are advised to monitor the SourceCodester website for security updates. In the absence of an official patch, organizations should implement the recommended workarounds and consider replacing the vulnerable system with a more secure alternative.

Additional vulnerability information is available through VulDB #349734.

Workarounds

• Modify the vulnerable PHP code to use prepared statements with parameterized queries instead of string concatenation
• Implement server-side input validation to reject any stock_name1 values containing special SQL characters
• Place the application behind a reverse proxy with SQL injection filtering capabilities
• Consider temporarily disabling the affected functionality until a proper fix can be implemented

# Example WAF rule for ModSecurity to block SQL injection attempts
SecRule ARGS:stock_name1 "@detectSQLi" \
    "id:1001,\
    phase:2,\
    deny,\
    status:403,\
    log,\
    msg:'SQL Injection attempt blocked in stock_name1 parameter'"