CVE-2024-4209 is a stored cross-site scripting vulnerability classified under CWE-79, found in the Gutenberg Blocks with AI by Kadence WP – Page Builder Features plugin for WordPress. The vulnerability affects all versions up to and including 3.2.36. It stems from improper neutralization of input during web page generation, specifically in the countdown timer block where user-supplied attributes are not adequately sanitized or escaped before being rendered. This allows authenticated attackers with contributor-level permissions or higher to inject arbitrary JavaScript code into pages. When other users access these pages, the injected scripts execute in their browsers, potentially compromising session tokens, redirecting users, or performing unauthorized actions on behalf of the victim. The vulnerability requires authentication but no additional user interaction beyond page access. The CVSS 3.1 vector (AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N) indicates network attack vector, low attack complexity, privileges required, no user interaction, and a scope change with limited confidentiality and integrity impact but no availability impact. No patches or exploits are currently publicly available, but the risk remains significant for sites using this plugin. The vulnerability highlights the importance of rigorous input validation and output encoding in WordPress plugin development to prevent persistent XSS attacks.

The primary impact of CVE-2024-4209 is the compromise of confidentiality and integrity on affected WordPress sites. Attackers with contributor-level access can inject malicious scripts that execute in the context of any user viewing the infected page, potentially leading to session hijacking, theft of sensitive information, unauthorized actions such as content modification or privilege escalation, and site defacement. This can damage the reputation of organizations, lead to data breaches, and undermine user trust. Since WordPress powers a significant portion of the web, and the Kadence plugin is popular among site builders, the vulnerability could affect a wide range of organizations, from small businesses to large enterprises relying on WordPress for their web presence. Although exploitation requires authenticated access, contributor-level permissions are commonly granted to trusted users, increasing the risk of insider threats or compromised accounts being leveraged. The lack of known exploits in the wild reduces immediate risk but does not eliminate the potential for future attacks. The vulnerability does not impact availability directly but can indirectly cause service disruptions through defacement or administrative lockout scenarios.

To mitigate CVE-2024-4209, organizations should first update the Gutenberg Blocks with AI by Kadence WP plugin to a version where the vulnerability is fixed once available. Until a patch is released, administrators should restrict contributor-level access strictly to trusted users and review existing user permissions to minimize exposure. Implementing a Web Application Firewall (WAF) with custom rules to detect and block suspicious input patterns targeting the countdown timer block can help prevent exploitation. Site owners should enable Content Security Policy (CSP) headers to limit the execution of unauthorized scripts. Regularly audit and sanitize user-generated content, especially in areas where contributors can input data. Monitoring site logs for unusual activity or injected scripts can provide early detection of exploitation attempts. Additionally, educating contributors about secure content practices and the risks of XSS can reduce inadvertent introduction of malicious code. Finally, maintain regular backups to enable quick recovery if an attack occurs.