CVE-2024-40111 identifies a stored cross-site scripting (XSS) vulnerability in Automad version 2.0.0-alpha.4, a flat file content management system (CMS). The vulnerability arises from insufficient sanitization of user input within the template body, allowing an attacker to inject malicious JavaScript code that is persistently stored in the CMS's flat file storage. When any user visits the affected forum or site, the malicious script executes in their browser context, potentially enabling session hijacking, credential theft, or unauthorized actions performed with the victim's privileges. The vulnerability requires the attacker to have high privileges (authenticated user) to inject the payload and also requires user interaction (visiting the infected page) for exploitation. The CVSS v3.1 base score is 4.8, reflecting medium severity due to the need for authentication and user interaction, and limited impact on availability. The vulnerability is classified under CWE-79 (Improper Neutralization of Input During Web Page Generation). No patches or known exploits have been reported at the time of publication, but the persistent nature of the XSS increases risk if exploited. The scope is considered changed (S:C) because the vulnerability affects components beyond the attacker’s privileges, impacting other users. This vulnerability highlights the risks of insufficient input validation in web applications, especially CMS platforms that store and render user-generated content.

The primary impact of CVE-2024-40111 is on the confidentiality and integrity of user data and sessions within affected Automad CMS installations. Attackers who successfully exploit this vulnerability can execute arbitrary JavaScript in the context of other users, potentially leading to session hijacking, theft of sensitive information such as cookies or credentials, and unauthorized actions performed on behalf of victims. Although availability is not directly impacted, the compromise of user accounts or administrative sessions could lead to further malicious activities including defacement or data manipulation. Since exploitation requires authenticated access and user interaction, the attack surface is somewhat limited, but the persistent nature of the injected script means that any user visiting the infected page is at risk. Organizations relying on Automad CMS for public-facing websites or forums could face reputational damage, loss of user trust, and potential regulatory consequences if sensitive user data is compromised. The lack of known exploits in the wild currently reduces immediate risk, but the vulnerability should be addressed promptly to prevent future exploitation.

To mitigate CVE-2024-40111, organizations should first verify if they are running Automad 2.0.0-alpha.4 or similar vulnerable versions and upgrade to a patched version once available. In the absence of an official patch, administrators should implement strict input validation and output encoding on all user-supplied content, especially within template bodies, to neutralize potentially malicious scripts. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers. Limit user privileges to the minimum necessary to reduce the risk of high-privilege attackers injecting malicious code. Regularly audit and sanitize existing content stored in the CMS to detect and remove any injected scripts. Additionally, monitor web traffic and logs for unusual activity indicative of XSS exploitation attempts. Educate users and administrators about the risks of XSS and encourage cautious behavior when interacting with user-generated content. Finally, consider deploying web application firewalls (WAFs) with rules designed to detect and block XSS payloads targeting Automad CMS.