CVE-2024-11582 is a stored cross-site scripting vulnerability identified in the Subscribe2 – Form, Email Subscribers & Newsletters plugin for WordPress, affecting all versions up to 10.43. The vulnerability stems from improper neutralization of input during web page generation, specifically through the 'ip' parameter, which lacks sufficient input sanitization and output escaping. This flaw allows unauthenticated attackers to inject arbitrary JavaScript code that is persistently stored and executed in the context of any user visiting the affected page. The attack vector requires no authentication or user interaction, making it highly exploitable remotely over the network. The vulnerability is classified under CWE-79 and has a CVSS 3.1 base score of 7.2, indicating a high severity level. The scope is 'changed' because the vulnerability affects resources beyond the attacker’s privileges, potentially impacting all users who access the injected content. The impact includes partial loss of confidentiality and integrity, as attackers can steal session tokens, manipulate page content, or perform actions on behalf of users. No direct impact on availability is noted. No official patches have been linked yet, but mitigation involves sanitizing and escaping user inputs properly. The vulnerability was publicly disclosed in February 2025, with no known active exploitation reported at the time. Given the widespread use of WordPress and the popularity of newsletter subscription plugins, this vulnerability poses a significant risk to websites relying on this plugin for subscriber management.

The primary impact of CVE-2024-11582 is on the confidentiality and integrity of affected websites and their users. Attackers exploiting this stored XSS vulnerability can execute arbitrary scripts in the context of users visiting the compromised pages, potentially leading to session hijacking, theft of sensitive information such as cookies or credentials, defacement of web content, or redirection to malicious websites. This can erode user trust, damage brand reputation, and lead to regulatory compliance issues, especially for sites handling personal data. Since the vulnerability requires no authentication or user interaction, it can be exploited at scale, affecting all visitors to the vulnerable site. Although availability is not directly impacted, secondary effects such as blacklisting by search engines or browsers could reduce site accessibility. Organizations using the Subscribe2 plugin are at risk of targeted attacks, especially those with high visitor traffic or handling sensitive subscriber information. The lack of a patch increases exposure time, raising the likelihood of exploitation once proof-of-concept code becomes available.

To mitigate CVE-2024-11582, organizations should immediately update the Subscribe2 plugin to a version that addresses this vulnerability once released by the vendor. In the absence of an official patch, administrators should consider temporarily disabling the plugin or restricting access to pages using it. Implementing a Web Application Firewall (WAF) with rules to detect and block malicious payloads targeting the 'ip' parameter can reduce risk. Additionally, site owners should audit and sanitize all user inputs rigorously, applying proper output encoding to prevent script injection. Regularly scanning the website for injected scripts and monitoring logs for suspicious activity is recommended. Employing Content Security Policy (CSP) headers can help mitigate the impact of XSS by restricting script execution sources. Finally, educating site administrators and users about the risks of XSS and maintaining a robust incident response plan will improve resilience against exploitation.