CVE-2024-13523 identifies a Cross-Site Request Forgery (CSRF) vulnerability in the MemorialDay plugin for WordPress, developed by shenyanzhi. The vulnerability exists in all versions up to 1.0.4 due to missing or incorrect nonce validation on a critical function that handles plugin settings updates. Nonces in WordPress are security tokens used to verify the legitimacy of requests to prevent CSRF attacks. The absence or improper implementation of nonce checks allows an attacker to craft a malicious request that, when executed by an authenticated administrator (via clicking a link or visiting a malicious page), can update plugin settings or inject malicious web scripts. This can lead to unauthorized changes in site behavior and potential cross-site scripting (XSS) attacks, compromising the confidentiality and integrity of the site’s data and user interactions. The vulnerability requires no privileges or authentication from the attacker but depends on successful social engineering to induce an administrator’s interaction. The CVSS 3.1 score of 6.1 reflects a medium severity with a network attack vector, low attack complexity, no privileges required, user interaction required, and a changed scope indicating that the attacker can affect resources beyond their initial privileges. No patches or official fixes are currently linked, and no known exploits have been reported in the wild, but the risk remains significant for sites using this plugin. The vulnerability is categorized under CWE-352, which is a common web security weakness related to CSRF attacks.

The primary impact of this vulnerability is the potential for unauthorized modification of plugin settings and injection of malicious scripts by attackers who can trick site administrators into performing actions unknowingly. This can lead to compromised site integrity, unauthorized data manipulation, and potential further exploitation such as persistent cross-site scripting (XSS). While availability is not directly affected, the confidentiality and integrity of the affected WordPress sites are at risk. Organizations relying on the MemorialDay plugin may face defacement, data leakage, or use of their site as a vector for broader attacks against their users. The attack requires social engineering, which may limit widespread exploitation but remains a serious risk for targeted attacks, especially against high-value or high-traffic WordPress sites. The vulnerability could also undermine trust in affected websites and lead to reputational damage.

To mitigate this vulnerability, organizations should first verify if they are using the MemorialDay plugin version 1.0.4 or earlier and upgrade to a patched version once available. In the absence of an official patch, administrators should implement strict administrative access controls and educate site administrators about the risks of clicking on suspicious links or visiting untrusted websites. Employing Web Application Firewalls (WAFs) with custom rules to detect and block CSRF attempts targeting the plugin’s endpoints can reduce risk. Additionally, site owners can implement manual nonce validation checks or temporarily disable the plugin if feasible until a patch is released. Regular monitoring of site logs for unusual administrative actions and scanning for injected scripts can help detect exploitation attempts early. Enforcing multi-factor authentication (MFA) for administrative accounts can also reduce the likelihood of successful exploitation by limiting unauthorized access even if CSRF is attempted.