CVE-2025-4396 in Relevanssi Plugin
Summary
by MITRE • 05/13/2025
The Relevanssi – A Better Search plugin for WordPress is vulnerable to time-based SQL Injection via the cats and tags query parameters in all versions up to, and including, 4.24.4 (Free) and <= 2.27.4 (Premium) due to insufficient escaping on the user supplied parameter and lack of sufficient preparation on the existing SQL query. This makes it possible for unauthenticated attackers to append additional SQL queries to already existing queries that can be used to extract sensitive information from the database.
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Analysis
by VulDB Data Team • 05/13/2025
The CVE-2025-4396 vulnerability affects the Relevanssi plugin for WordPress, specifically targeting both free and premium versions up to 4.24.4 and 2.27.4 respectively. This time-based SQL injection flaw exists within the plugin's search functionality where attackers can manipulate the cats and tags query parameters to inject malicious SQL code. The vulnerability stems from inadequate input sanitization and improper SQL query preparation mechanisms that fail to properly escape user-supplied parameters before incorporating them into database queries.
The technical exploitation of this vulnerability occurs through time-based SQL injection techniques where attackers can craft malicious payloads that cause the database to delay responses based on boolean conditions. When the plugin processes the cats and tags parameters without proper sanitization, an attacker can append SQL statements that force the database to sleep or perform complex operations, thereby leaking information through response timing differences. This approach allows attackers to extract sensitive data such as user credentials, database schema information, and other confidential data through careful timing analysis of database responses.
The operational impact of this vulnerability is significant as it affects unauthenticated attackers who can exploit the flaw without requiring prior login credentials or administrative privileges. The vulnerability directly violates the principle of least privilege and demonstrates a critical failure in input validation and database query construction practices. Attackers can potentially extract complete database contents, user account information, and other sensitive data that could lead to full system compromise and data breaches.
Mitigation strategies should include immediate plugin updates to versions that address the SQL injection vulnerability, implementing proper input validation and parameterized queries, and applying web application firewalls to monitor and block suspicious query patterns. Organizations should also conduct thorough security assessments of their WordPress installations and implement proper database access controls to limit the potential impact of such vulnerabilities. This vulnerability aligns with CWE-89 which specifically addresses SQL injection flaws and represents a clear violation of the OWASP Top Ten security principles, particularly the use of secure coding practices and proper input validation techniques. The ATT&CK framework categorizes this as a database reconnaissance technique where attackers gather information about database structures and contents through indirect means, potentially leading to privilege escalation and data exfiltration operations.