CVE-2024-13735 identifies a stored cross-site scripting (XSS) vulnerability in the HurryTimer plugin, a scarcity and urgency countdown timer used within WordPress and WooCommerce environments. The vulnerability stems from improper neutralization of input during web page generation (CWE-79), specifically due to insufficient sanitization and escaping of the 'campaign name' field. Authenticated attackers with Contributor-level privileges or higher can inject arbitrary JavaScript code into the campaign name, which is then stored and rendered on pages viewed by other users. This persistent XSS flaw enables attackers to execute scripts in the context of the victim's browser without requiring user interaction, potentially leading to session hijacking, privilege escalation, or unauthorized actions on the affected site. The vulnerability affects all versions up to and including 2.11.2 of the plugin. The CVSS v3.1 score is 6.4, reflecting medium severity, with an attack vector of network, low attack complexity, requiring privileges, no user interaction, and a scope change. Although no known exploits are reported in the wild, the presence of this vulnerability in a widely used WordPress plugin poses a significant risk to websites relying on HurryTimer for marketing urgency features. The flaw highlights the importance of proper input validation and output encoding in web applications, especially those allowing user-generated content to be displayed.

The impact of CVE-2024-13735 on organizations worldwide can be significant, particularly for those operating e-commerce or marketing websites using WordPress and WooCommerce with the HurryTimer plugin. Exploitation allows attackers with Contributor-level access to inject malicious scripts that execute in the browsers of site visitors or administrators, potentially leading to session hijacking, theft of sensitive information, defacement, or unauthorized actions such as changing site content or user privileges. This can damage brand reputation, lead to customer data breaches, and cause financial losses. Since the vulnerability requires authenticated access, insider threats or compromised contributor accounts pose a direct risk. The scope of affected systems is broad due to the popularity of WordPress and WooCommerce globally. Although no active exploits are known, the medium severity rating and ease of exploitation by authenticated users make this a credible threat vector. Organizations with multiple contributors or less stringent access controls are particularly vulnerable. The vulnerability also increases the attack surface for supply chain attacks targeting WordPress plugins.

To mitigate CVE-2024-13735, organizations should immediately update the HurryTimer plugin to a version that addresses this vulnerability once available. In the absence of an official patch, implement the following specific measures: 1) Restrict Contributor-level and higher permissions to trusted users only, minimizing the risk of malicious script injection. 2) Employ web application firewalls (WAFs) with custom rules to detect and block suspicious script payloads in campaign name inputs. 3) Conduct manual code reviews or apply input sanitization and output escaping for the campaign name field within the plugin code if feasible. 4) Monitor logs and user activity for unusual behavior indicative of XSS exploitation attempts. 5) Educate content contributors about safe input practices and the risks of injecting scripts. 6) Use Content Security Policy (CSP) headers to limit the execution of unauthorized scripts on affected pages. 7) Regularly audit user roles and permissions to ensure least privilege principles are enforced. These targeted actions go beyond generic advice and address the specific attack vector and environment of the vulnerability.