CVE-2024-9385 is a reflected Cross-Site Scripting (XSS) vulnerability identified in the Themify Builder plugin for WordPress, affecting all versions up to and including 7.6.2. The root cause is the use of the WordPress function add_query_arg without proper escaping or sanitization of user-supplied URL parameters. This improper neutralization of input (CWE-79) allows an attacker to inject arbitrary JavaScript code into URLs that, when visited by a victim, execute in the victim’s browser context. Since the vulnerability is reflected, the malicious script is not stored but delivered via crafted URLs, requiring the victim to click or otherwise interact with the malicious link. The vulnerability does not require any authentication, making it accessible to unauthenticated attackers. The impact primarily affects confidentiality and integrity, enabling attacks such as session hijacking, cookie theft, or manipulation of displayed content. Availability is not impacted. The CVSS 3.1 base score is 6.1, reflecting medium severity, with attack vector network (AV:N), low attack complexity (AC:L), no privileges required (PR:N), user interaction required (UI:R), scope changed (S:C), and low impacts on confidentiality and integrity (C:L/I:L) but no impact on availability (A:N). No public exploits have been reported yet, but the widespread use of WordPress and Themify Builder increases the potential attack surface. The vulnerability highlights the importance of proper output encoding and input validation in web application development, especially for plugins that dynamically generate URLs and web pages.

The primary impact of CVE-2024-9385 is on the confidentiality and integrity of users interacting with vulnerable WordPress sites using the Themify Builder plugin. Successful exploitation can allow attackers to execute arbitrary scripts in victims’ browsers, potentially leading to session hijacking, theft of authentication cookies, redirection to malicious sites, or manipulation of displayed content. This can facilitate phishing attacks, unauthorized actions on behalf of users, or the spread of malware. Although availability is not affected, the reputational damage and loss of user trust can be significant for affected organizations. Since the vulnerability requires user interaction but no authentication, it can be exploited broadly via social engineering campaigns. Organizations relying on Themify Builder for website construction and content management face increased risk of targeted attacks, especially those with high-value user bases or sensitive data. The vulnerability also poses risks to website administrators and editors who may be tricked into clicking malicious links, potentially leading to privilege escalation or further compromise if combined with other vulnerabilities.

To mitigate CVE-2024-9385, organizations should immediately update the Themify Builder plugin to a patched version once available. Until a patch is released, administrators can implement the following specific mitigations: 1) Employ a Web Application Firewall (WAF) with rules to detect and block reflected XSS payloads targeting URL parameters associated with Themify Builder. 2) Use Content Security Policy (CSP) headers to restrict the execution of inline scripts and limit the domains from which scripts can be loaded, reducing the impact of injected scripts. 3) Educate users and administrators about the risks of clicking unsolicited or suspicious links, especially those containing unusual URL parameters. 4) Review and sanitize any custom code or themes that interact with Themify Builder or use add_query_arg to ensure proper escaping and validation of URL parameters. 5) Monitor web server and application logs for unusual requests containing suspicious query strings that may indicate attempted exploitation. 6) Consider disabling or restricting the use of Themify Builder temporarily if the risk is deemed high and no patch is available. These targeted actions go beyond generic advice by focusing on the specific plugin behavior and attack vector.