CVE-2023-2995 in Leyka Plugin
Summary
by MITRE • 09/19/2023
The Leyka WordPress plugin through 3.30.3 does not sanitise and escape some of its settings, which could allow high privilege users such as admin to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed (for example in multisite setup)
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Analysis
by VulDB Data Team • 09/22/2023
The CVE-2023-2995 vulnerability affects the Leyka WordPress plugin version 3.30.3 and earlier, presenting a significant security risk through stored cross-site scripting flaws. This vulnerability specifically targets high-privilege users including administrators who possess the ability to manipulate plugin settings. The flaw stems from inadequate sanitization and escaping of user-provided input within the plugin's configuration parameters, creating an environment where malicious scripts can be persistently injected and executed. The vulnerability is particularly concerning in multisite WordPress environments where the unfiltered_html capability is typically restricted to prevent such attacks. The issue demonstrates a failure in proper input validation and output escaping mechanisms that are fundamental to preventing XSS vulnerabilities.
The technical implementation of this vulnerability occurs within the plugin's settings handling code where user inputs are stored without proper sanitization processes. When administrators configure plugin settings through the WordPress admin interface, the malicious payloads are stored in the database and subsequently rendered in subsequent page requests without appropriate HTML escaping. This creates a persistent XSS vector that can affect any user who views pages containing the maliciously stored content. The vulnerability operates at the application layer and requires minimal privileges to exploit, as it targets administrative users who can modify plugin configurations. The attack scenario involves an attacker with administrative access crafting malicious scripts within plugin settings, which then execute in the browsers of other users who visit affected pages.
The operational impact of CVE-2023-2995 extends beyond simple script execution, potentially enabling attackers to escalate privileges, steal session cookies, perform actions on behalf of victims, and access sensitive administrative functions. In multisite environments where unfiltered_html is restricted, the vulnerability becomes particularly dangerous as it bypasses the intended security controls designed to prevent XSS attacks. The stored nature of the vulnerability means that malicious scripts remain active until manually removed from the plugin settings, creating persistent threats that can affect multiple users over extended periods. This vulnerability aligns with CWE-79 which identifies Cross-Site Scripting as a critical weakness in web applications, and represents a failure in the principle of least privilege as it allows administrative users to introduce malicious content that can affect all users of the affected system.
Organizations should implement immediate mitigations including upgrading to the latest version of the Leyka plugin where the vulnerability has been addressed, applying the most recent security patches, and conducting thorough reviews of plugin settings for any malicious content. System administrators should also implement additional security controls such as content security policies to limit the impact of potential XSS attacks, monitor plugin configuration changes for suspicious activities, and ensure proper access controls are maintained. The vulnerability demonstrates the importance of proper input sanitization and output escaping in web applications and highlights the need for comprehensive security testing of third-party plugins. Security teams should also consider implementing web application firewalls and regular security audits to detect and prevent similar vulnerabilities in other components of their WordPress installations. The ATT&CK framework categorizes this vulnerability under T1566 for Phishing and T1059 for Command and Scripting Interpreter, as it enables attackers to establish persistent access through malicious script execution.