CVE-2026-6189: Pharmacy Sales Inventory System SQLi Flaw

CVE-2026-6189 Overview

A SQL injection vulnerability has been discovered in SourceCodester Pharmacy Sales and Inventory System version 1.0. The vulnerability exists in the login functionality at /ajax.php?action=login, where the Username parameter is susceptible to SQL injection attacks. This flaw allows remote attackers to manipulate database queries by injecting malicious SQL code through the authentication endpoint.

Critical Impact
Unauthenticated remote attackers can exploit this SQL injection vulnerability to bypass authentication, extract sensitive data from the database, or potentially modify pharmacy inventory and sales records.

Affected Products

SourceCodester Pharmacy Sales and Inventory System 1.0
Systems utilizing the vulnerable /ajax.php?action=login endpoint
PHP-based pharmacy management systems derived from this codebase

Discovery Timeline

April 13, 2026 - CVE-2026-6189 published to NVD
April 13, 2026 - Last updated in NVD database

Technical Details for CVE-2026-6189

Vulnerability Analysis

This SQL injection vulnerability (CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component) affects the login handler in the Pharmacy Sales and Inventory System. The application fails to properly sanitize or parameterize user-supplied input in the Username field before incorporating it into SQL queries. When authentication requests are processed through the /ajax.php?action=login endpoint, the username value is directly concatenated into the database query without proper escaping or prepared statement usage.

The network-accessible nature of this vulnerability allows attackers to exploit it remotely without any prior authentication or user interaction. The exploit has been publicly disclosed, increasing the risk of active exploitation in the wild.

Root Cause

The root cause is improper input validation and the absence of parameterized queries in the authentication mechanism. The Username parameter from POST requests is directly interpolated into SQL statements, creating a classic SQL injection vulnerability. This is a common flaw in PHP applications that use string concatenation to build database queries rather than utilizing prepared statements with bound parameters.

Attack Vector

The attack can be executed remotely over the network by sending crafted HTTP POST requests to the /ajax.php?action=login endpoint. An attacker can manipulate the Username parameter to inject malicious SQL syntax that alters the intended query logic. Common exploitation techniques include:

Authentication bypass: Injecting SQL fragments like ' OR '1'='1 to bypass login validation
Data exfiltration: Using UNION-based or blind SQL injection to extract database contents
Database manipulation: Modifying or deleting pharmacy inventory and sales records

The vulnerability allows attackers to manipulate the application's SQL queries without requiring authentication, making it particularly dangerous for internet-facing deployments. Technical details and exploitation information have been documented in the GitHub Issue Discussion and VulDB Vulnerability Report.

Detection Methods for CVE-2026-6189

Indicators of Compromise

HTTP POST requests to /ajax.php?action=login containing SQL metacharacters (single quotes, double dashes, UNION keywords) in the Username parameter
Unusual database query patterns or errors in application logs indicating injection attempts
Failed login attempts with abnormal username values containing SQL syntax
Unexpected database access or data modifications in pharmacy inventory records

Detection Strategies

Deploy Web Application Firewall (WAF) rules to detect and block SQL injection patterns in POST parameters
Monitor HTTP traffic for requests containing common SQL injection payloads targeting the /ajax.php?action=login endpoint
Implement database activity monitoring to detect anomalous query patterns or unauthorized data access
Review web server logs for suspicious login attempts with encoded or obfuscated SQL injection strings

Monitoring Recommendations

Enable detailed logging for all authentication-related requests to the affected endpoint
Configure alerts for multiple failed login attempts with varying SQL-like username patterns
Implement database audit logging to track query execution and detect injection attempts
Deploy intrusion detection systems (IDS) with signatures for SQL injection attack patterns

How to Mitigate CVE-2026-6189

Immediate Actions Required

Restrict network access to the Pharmacy Sales and Inventory System to trusted networks or VPN only
Implement input validation at the web server or reverse proxy level to filter SQL metacharacters
Consider taking the application offline until a patch is available or code remediation is complete
Review database logs for evidence of prior exploitation and assess potential data compromise

Patch Information

No official vendor patch has been identified at this time. The vulnerability has been disclosed publicly through VulDB and community channels. Administrators should monitor SourceCodester for potential updates or security advisories. Given the nature of open-source PHP projects on SourceCodester, organizations may need to implement manual code fixes.

Workarounds

Implement prepared statements with parameterized queries in the /ajax.php login handler code
Deploy a Web Application Firewall (WAF) with SQL injection protection rules in front of the application
Add server-side input validation to reject username values containing SQL special characters
Restrict database user privileges to minimize the impact of successful SQL injection attacks
Consider using a security plugin or middleware that provides SQL injection protection for PHP applications

For manual remediation, modify the login authentication code to use PDO prepared statements or MySQLi parameterized queries. The Username parameter should be bound as a parameter rather than concatenated into the SQL string. Additional technical references are available at the VulDB CTI Information page.