CVE-2025-2935 is a Cross-Site Request Forgery (CSRF) vulnerability affecting the WordPress plugin 'Anti-Spam: Spam Protection | Block Spam Users, Comments, Forms' developed by mcitar. This vulnerability exists in all versions up to and including 2024.7 due to missing or incorrect nonce validation in the plugin files 'ss_option_maint.php' and 'ss_user_filter_list'. Nonces in WordPress are security tokens used to verify that a request comes from a legitimate source, typically to prevent CSRF attacks. The absence or improper implementation of nonce validation allows an unauthenticated attacker to craft malicious requests that, when executed by an authenticated site administrator (e.g., by clicking a link), can perform unauthorized actions. Specifically, the attacker can delete pending comments and re-enable previously blocked users without the administrator’s explicit consent. This attack vector leverages the trust relationship between the administrator’s browser session and the WordPress site, exploiting the administrator’s privileges. The vulnerability has a CVSS 3.1 base score of 5.4 (medium severity), with the vector indicating network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), user interaction required (UI:R), unchanged scope (S:U), and low impact on confidentiality and integrity (C:L, I:L) but no impact on availability (A:N). There are no known exploits in the wild at the time of publication, and no patches have been linked yet. The vulnerability is classified under CWE-352, which is a common weakness related to CSRF attacks.

For European organizations using WordPress websites with the affected mcitar Anti-Spam plugin, this vulnerability poses a moderate risk. An attacker could manipulate site administrators into performing unintended actions, such as deleting legitimate pending comments or re-enabling blocked spam users, which could degrade the quality of user-generated content and spam protection effectiveness. This can lead to reputational damage, reduced user trust, and increased administrative overhead to manually correct the effects. Although the vulnerability does not directly compromise sensitive data or system availability, it undermines the integrity of the website’s content moderation and spam control mechanisms. For organizations relying heavily on community engagement or user feedback via comments, this could disrupt normal operations. Additionally, if attackers combine this with social engineering campaigns targeting administrators, the risk of successful exploitation increases. The medium severity score reflects the limited but tangible impact on integrity and the requirement for user interaction, which somewhat limits exploitation scope.

To mitigate this vulnerability, European organizations should first verify if they are using the affected plugin version (up to 2024.7) and plan to update to a patched version once available. In the absence of an official patch, administrators can implement the following specific measures: 1) Disable or restrict the plugin’s functionality temporarily, especially the features related to comment moderation and user blocking, until a fix is applied. 2) Educate site administrators about the risks of clicking on unsolicited links or performing administrative actions from untrusted sources to reduce the likelihood of social engineering exploitation. 3) Implement additional web application firewall (WAF) rules to detect and block suspicious POST requests targeting the vulnerable plugin endpoints ('ss_option_maint.php' and 'ss_user_filter_list'). 4) Employ security plugins or custom code to enforce nonce validation or CSRF tokens on the affected plugin’s actions as an interim protective measure. 5) Regularly audit user roles and permissions to ensure that only trusted users have administrative privileges capable of triggering these actions. 6) Monitor logs for unusual administrative activity that could indicate exploitation attempts. These targeted steps go beyond generic advice by focusing on the plugin’s specific weak points and operational context.