SQL Injection in Multi-Vendor Online Grocery Management System

Executive Summary

CVE-2026-14695 is a SQL injection vulnerability found in the Multi-Vendor Online Grocery Management System version 1.0, specifically in the registration functions save_client() and save_vendor() within the classes/Users.php file.

The vulnerability occurs because the application dynamically builds SQL INSERT statements by iterating over all POST parameters, wrapping field names in backticks and values in single quotes. While the values are properly escaped, the field names (keys) are not validated or escaped.

An attacker can exploit this by submitting a POST request with specially crafted field names containing backtick characters, which prematurely terminate the column name quoting and allow injection of additional column assignments into the SQL statement.

This enables the attacker to manipulate account status, override business logic defaults, or set arbitrary columns during registration, such as blocking a newly created account immediately upon login.

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Impact Analysis

This vulnerability can allow an unauthenticated attacker to manipulate account states or override default business logic during user or vendor registration.

For example, an attacker could block newly created accounts by injecting a status value, potentially disrupting legitimate user access.

Additionally, if the attacker has knowledge of the database schema, they might perform further SQL injection attacks, leading to unauthorized data access or modification.

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Detection Guidance

This vulnerability can be detected by monitoring for unusual or suspicious POST requests to the registration endpoints, specifically targeting the save_client() and save_vendor() functions in the /classes/Users.php file.

Look for POST parameters where the field names contain backtick (`) characters or other special characters that could prematurely terminate SQL column quoting.

A practical detection method is to capture and analyze HTTP POST requests to the registration endpoints and check for field names with embedded backticks or unexpected SQL syntax.

Example command using curl to test for the vulnerability by injecting a backtick in a field name:

• curl -X POST -d "status=0,`delete_flag=1" http://target-site/path-to-registration-endpoint

Additionally, network intrusion detection systems (NIDS) or web application firewalls (WAF) can be configured to alert on POST requests containing backticks or suspicious SQL injection patterns in parameter names.

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Mitigation Strategies

Immediate mitigation steps include implementing strict input validation and sanitization on the registration endpoints to reject any field names containing special characters such as backticks.

Whitelist allowed registration fields explicitly, ensuring only expected parameter names are accepted.

Refactor the code to use prepared statements that separate SQL column names from user input values, preventing injection via field names.

Apply these fixes to both the save_client() and save_vendor() functions to cover all affected registration handlers.

In the short term, consider blocking or filtering POST requests with suspicious parameter names at the web server or firewall level.

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Compliance Impact

The vulnerability allows an attacker to manipulate SQL queries by injecting malicious column assignments during user registration, potentially leading to unauthorized data access or manipulation.

Such unauthorized access or manipulation of personal or sensitive data could lead to non-compliance with data protection regulations like GDPR or HIPAA, which require safeguarding personal data against unauthorized access and ensuring data integrity.

Therefore, exploitation of this vulnerability could result in violations of these standards due to compromised confidentiality, integrity, and possibly availability of protected data.

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