CVE-2022-3753 in Evaluate Plugin
Summary
by MITRE • 11/21/2022
The Evaluate WordPress plugin through 1.0 does not sanitize and escapes 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 • 12/21/2022
The CVE-2022-3753 vulnerability affects the Evaluate WordPress plugin version 1.0 and represents a critical stored cross-site scripting flaw that undermines the security posture of WordPress installations. This vulnerability specifically targets the plugin's handling of user settings without proper sanitization and escaping mechanisms, creating an attack vector that can be exploited by users with administrative privileges. The flaw is particularly concerning because it persists in the system's database and can affect multiple users who interact with the compromised plugin functionality. The vulnerability operates by allowing malicious script code to be stored within the plugin's settings and subsequently executed when other users view the affected pages, making it a classic stored XSS attack scenario. The issue becomes more pronounced in multisite WordPress environments where the unfiltered_html capability is typically restricted to prevent arbitrary HTML injection, yet the vulnerability circumvents these protections through improper input handling.
The technical root cause of this vulnerability stems from the plugin's failure to properly sanitize user inputs before storing them in the database and subsequently outputting them to web pages. This improper handling violates fundamental security principles for input validation and output escaping that are essential for preventing XSS attacks. The vulnerability specifically impacts the plugin's settings management functionality where user-provided data is not adequately filtered through WordPress's built-in sanitization functions. According to CWE standards, this represents a CWE-79: Improper Neutralization of Input During Web Page Generation, which is a well-documented category of web application vulnerabilities that directly enables XSS attacks. The flaw allows attackers with administrative privileges to inject malicious scripts that can execute in the context of other users' browsers, potentially leading to session hijacking, data theft, or further compromise of the affected WordPress installation.
The operational impact of CVE-2022-3753 extends beyond simple script execution as it fundamentally compromises the integrity of the WordPress administration interface and user interactions. When exploited, the stored XSS vulnerability can enable attackers to perform actions such as stealing administrator session cookies, redirecting users to malicious sites, modifying plugin settings, or even installing additional malware through the compromised administrative interface. The vulnerability's persistence in the database means that the malicious code remains active until manually removed from the plugin's configuration, potentially affecting all users who access the affected WordPress site. In multisite environments, this vulnerability becomes even more dangerous as it can potentially affect multiple sites within the network if the malicious code is injected through a single compromised administrative account. The attack surface is broadened because the vulnerability can be exploited even when WordPress security measures like unfiltered_html restrictions are in place, making it particularly insidious in hardened environments.
Mitigation strategies for CVE-2022-3753 require immediate attention from WordPress administrators and security teams responsible for maintaining affected installations. The most effective immediate solution involves updating to a patched version of the Evaluate plugin if available, or temporarily disabling the plugin until a secure update can be implemented. Organizations should also implement additional defensive measures such as monitoring for suspicious plugin settings changes, implementing stricter input validation at the network level, and conducting thorough security audits of all installed plugins. From an ATT&CK framework perspective, this vulnerability maps to T1548.001: Abuse Elevation Control Mechanism, as it allows privilege escalation through the exploitation of administrative capabilities. Security teams should also consider implementing Content Security Policy (CSP) headers as an additional defense-in-depth measure to limit the execution of unauthorized scripts, though this approach provides only partial protection against stored XSS attacks. Regular security scanning of WordPress installations for vulnerable plugins and maintaining updated security practices including timely patch management, proper user privilege management, and monitoring for anomalous administrative activities are essential components of a comprehensive defense strategy against this type of vulnerability.