The CVE-2025-49283 vulnerability is a Cross-Site Request Forgery (CSRF) weakness identified in the Matthias Nordwig Anti-spam, Spam protection, ReCaptcha for all forms and GDPR-compliant plugin, affecting versions up to 4.1.1. CSRF vulnerabilities allow an attacker to trick an authenticated user into submitting unwanted actions on a web application in which they are currently authenticated. In this case, the vulnerability could enable an attacker to perform unauthorized actions on behalf of a legitimate user without their consent or knowledge. The CVSS 3.1 base score of 4.3 (medium severity) reflects that the attack vector is network-based (AV:N), requires no privileges (PR:N), but does require user interaction (UI:R), and impacts integrity (I:L) without affecting confidentiality or availability. The vulnerability does not require authentication and can be exploited remotely, but the need for user interaction (such as clicking a crafted link or visiting a malicious website) limits the ease of exploitation somewhat. The affected product is a WordPress plugin designed to provide anti-spam and ReCaptcha functionality across forms while ensuring GDPR compliance. Since this plugin is integrated into websites to protect form submissions, a successful CSRF attack could allow an attacker to manipulate form submissions or change plugin settings, potentially bypassing spam protections or altering site behavior. No known exploits are currently reported in the wild, and no patches or fixes have been linked yet. The vulnerability is categorized under CWE-352, which is a common web security weakness related to insufficient anti-CSRF protections such as missing or ineffective CSRF tokens or validation mechanisms.

For European organizations, especially those operating websites that utilize the Matthias Nordwig Anti-spam plugin, this vulnerability could lead to unauthorized form submissions or changes to spam protection settings. This may result in increased spam, abuse of web forms, or manipulation of user interactions, potentially undermining GDPR compliance if user data is mishandled or exposed indirectly. The integrity of form data and site configuration could be compromised, leading to reputational damage and possible regulatory scrutiny under GDPR if personal data is affected. While the vulnerability does not directly impact confidentiality or availability, the indirect effects on data integrity and user trust can be significant. Organizations relying on this plugin for critical form protection should be aware that attackers could exploit this CSRF flaw to bypass anti-spam measures or inject malicious form data, which could facilitate further attacks such as phishing or social engineering. Given the plugin’s role in GDPR compliance, exploitation could also raise compliance risks if user consent or data handling processes are manipulated.

European organizations should immediately review their use of the Matthias Nordwig Anti-spam plugin and monitor for updates or patches from the vendor. Until a patch is available, practical mitigations include: 1) Implementing additional CSRF protections at the web application or server level, such as validating the HTTP Referer header or enforcing same-site cookies to restrict cross-origin requests. 2) Employing Web Application Firewalls (WAFs) with rules designed to detect and block suspicious CSRF attempts targeting the plugin’s endpoints. 3) Educating users and administrators about the risks of clicking on unsolicited links or visiting untrusted websites while authenticated to sensitive web applications. 4) Reviewing and tightening user session management and cookie security settings (e.g., setting cookies with the SameSite attribute to 'Strict' or 'Lax'). 5) Conducting security audits of the affected web applications to identify any abnormal form submissions or configuration changes. 6) Considering temporary disabling or replacing the vulnerable plugin with alternative anti-spam solutions that have verified CSRF protections until the vendor releases a fix.