CVE-2021-24405 in Easy Cookies Policy Plugin
Summary
by MITRE • 07/06/2021
The Easy Cookies Policy WordPress plugin through 1.6.2 is lacking any capability and CSRF check when saving its settings, allowing any authenticated users (such as subscriber) to change them. If users can't register, this can be done through CSRF. Furthermore, the cookie banner setting is not sanitised or validated before being output in all pages of the frontend and the backend settings one, leading to a Stored Cross-Site Scripting issue.
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Analysis
by VulDB Data Team • 05/03/2025
The CVE-2021-24405 vulnerability affects the Easy Cookies Policy WordPress plugin version 1.6.2 and earlier, presenting a critical security flaw that exploits insufficient access controls and input validation mechanisms. This vulnerability stems from the plugin's failure to implement proper authentication checks and Cross-Site Request Forgery protections when processing configuration changes, creating a privilege escalation vector that allows low-privilege users to modify sensitive plugin settings. The flaw specifically targets the plugin's settings management functionality, where any authenticated user regardless of their role can manipulate the cookie policy configuration without proper authorization checks. This issue becomes particularly dangerous when combined with the plugin's lack of input sanitization for cookie banner settings, which creates a persistent stored cross-site scripting vulnerability that can affect all users interacting with the affected website.
The technical implementation of this vulnerability demonstrates a clear violation of security best practices and can be categorized under CWE-352 for Cross-Site Request Forgery and CWE-116 for improper output sanitization. The plugin's settings save functionality operates without verifying user credentials or implementing CSRF tokens, allowing any authenticated user to submit malicious requests that modify the plugin's configuration parameters. When users register is disabled on a WordPress site, attackers can leverage CSRF techniques to exploit this vulnerability without needing to create legitimate accounts, effectively bypassing the authentication requirement. The stored XSS component emerges from the plugin's failure to sanitize user-provided input before rendering it in both frontend and backend contexts, creating a persistent threat that executes malicious scripts whenever affected pages are loaded.
The operational impact of this vulnerability extends beyond simple configuration changes, as it creates a persistent threat that can be leveraged by attackers to compromise user sessions and execute malicious code within the context of the affected website. Low-privilege users such as subscribers can potentially modify cookie policy settings to redirect users to malicious domains, display fraudulent content, or inject malicious scripts that could harvest user credentials or perform other malicious activities. The stored XSS vulnerability poses a significant risk to all website visitors, as the malicious scripts execute automatically whenever users access pages that render the affected cookie banner content. This vulnerability can be particularly devastating in environments where the plugin is widely used, as it could affect multiple websites simultaneously and potentially lead to widespread session hijacking or data exfiltration attacks. The combination of privilege escalation and persistent XSS creates a multi-vector attack surface that significantly amplifies the overall security risk.
Mitigation strategies for CVE-2021-24405 should prioritize immediate plugin updates to versions that address the CSRF and input sanitization issues. Administrators must implement proper access controls and CSRF protection mechanisms within the plugin's settings management functionality, ensuring that all configuration changes require proper authentication and token validation. Input sanitization should be enforced for all user-provided content, particularly for cookie banner settings and other configurable elements that are rendered in the frontend interface. Security monitoring should include detection of unauthorized configuration changes and potential XSS payloads within the plugin's settings. Organizations should also consider implementing web application firewalls and content security policies to provide additional layers of protection against exploitation attempts. The vulnerability highlights the critical importance of proper input validation and access control implementation in WordPress plugins, aligning with ATT&CK techniques that focus on privilege escalation and code injection vulnerabilities. Regular security audits of third-party plugins and timely updates remain essential practices to prevent exploitation of similar vulnerabilities in the WordPress ecosystem.