CVE-2024-8664 is a reflected cross-site scripting (XSS) vulnerability identified in the WP Test Email plugin for WordPress, developed by boopathi0001. The flaw exists in all plugin versions up to and including 1.1.7 due to the use of the WordPress function add_query_arg without proper escaping of URL parameters. This improper neutralization of input (CWE-79) allows unauthenticated attackers to craft malicious URLs that inject arbitrary JavaScript code into web pages generated by the plugin. When a victim clicks on such a crafted link, the injected script executes in their browser context, potentially leading to session hijacking, credential theft, or redirection to malicious sites. The vulnerability is classified as reflected XSS because the malicious payload is reflected off the web server in the response. Exploitation does not require authentication but does require user interaction (clicking a link). The CVSS v3.1 base score is 6.1, indicating medium severity, with attack vector network (remote), low attack complexity, no privileges required, user interaction required, and impacts on confidentiality and integrity but not availability. No patches or fixes are currently linked, and no known exploits have been reported in the wild as of the publication date. The vulnerability affects all versions of the plugin, which is used in WordPress environments primarily for testing email functionality. The plugin’s market penetration is limited compared to major plugins but still represents a risk for sites using it without updates or mitigations.

The primary impact of CVE-2024-8664 is on the confidentiality and integrity of affected WordPress sites and their users. Successful exploitation can allow attackers to execute arbitrary scripts in the context of a victim’s browser, potentially leading to session hijacking, theft of cookies or credentials, phishing attacks, or unauthorized actions performed on behalf of the user. While the vulnerability does not affect availability, the compromise of user sessions or administrative accounts can lead to further exploitation or site defacement. Organizations using the WP Test Email plugin are at risk of targeted attacks, especially if users can be socially engineered to click malicious links. The scope is limited to sites running the vulnerable plugin, but given WordPress’s widespread use, the overall risk is non-negligible. The lack of authentication requirement lowers the barrier for attackers, but the need for user interaction reduces the likelihood of automated mass exploitation. No known active exploits reduce immediate risk, but the vulnerability should be addressed promptly to prevent future attacks.

To mitigate CVE-2024-8664, organizations should first check if they are using the WP Test Email plugin and identify the version installed. Since no official patches are currently linked, users should monitor the plugin’s repository or vendor announcements for updates addressing this issue. In the interim, administrators can implement the following specific mitigations: 1) Disable or remove the WP Test Email plugin if it is not essential to reduce the attack surface. 2) Employ web application firewalls (WAFs) with rules to detect and block reflected XSS payloads targeting the plugin’s URL patterns. 3) Use Content Security Policy (CSP) headers to restrict the execution of inline scripts and reduce the impact of injected scripts. 4) Educate users and administrators about the risks of clicking unsolicited or suspicious links, especially those containing unusual URL parameters. 5) Review and sanitize any custom code or themes that interact with the plugin or its URL parameters to ensure proper escaping. 6) Regularly audit WordPress plugins and update them promptly when security patches become available. These targeted steps go beyond generic advice by focusing on the specific plugin and vulnerability vector.