CVE-2025-6055 is a Cross-Site Request Forgery (CSRF) vulnerability affecting the Zen Sticky Social plugin for WordPress, developed by bogdanding. This vulnerability exists in all versions up to and including version 0.3 due to missing or incorrect nonce validation on the 'zen-social-sticky/zen-sticky-social.php' page. Nonces are security tokens used to verify that requests made to a web application are intentional and originate from authenticated users. The absence or improper implementation of nonce validation allows an unauthenticated attacker to craft malicious requests that, when executed by an authenticated site administrator (for example, by clicking a specially crafted link), can update plugin settings and inject malicious scripts into the website. This can lead to unauthorized changes in the plugin configuration and potential cross-site scripting (XSS) attacks, which may compromise the integrity and confidentiality of the site. The vulnerability has a CVSS v3.1 base score of 6.1, indicating a medium severity level. The attack vector is network-based (remote), requires no privileges, but does require user interaction (the administrator must be tricked into clicking a malicious link). The scope is changed, meaning the vulnerability can affect resources beyond the initially vulnerable component, potentially impacting the entire WordPress site. No known exploits are currently reported in the wild, and no patches have been published yet. The vulnerability is classified under CWE-352, which specifically relates to CSRF issues where attackers exploit the trust a site has in a user's browser to perform unauthorized actions.

For European organizations using WordPress websites with the Zen Sticky Social plugin, this vulnerability poses a significant risk. Successful exploitation can lead to unauthorized modification of plugin settings and injection of malicious scripts, potentially enabling attackers to conduct further attacks such as persistent XSS, session hijacking, or phishing campaigns targeting site visitors or administrators. This can result in data leakage, defacement, loss of user trust, and reputational damage. Since WordPress powers a substantial portion of websites across Europe, including those of SMEs, public institutions, and e-commerce platforms, the impact can be widespread. Organizations handling sensitive customer data or critical services may face regulatory consequences under GDPR if personal data confidentiality or integrity is compromised. Additionally, the requirement for user interaction (administrator clicking a malicious link) means targeted social engineering campaigns could be effective, especially in environments with less stringent security awareness. The vulnerability does not directly affect availability but can indirectly disrupt operations if the site is defaced or taken offline for remediation.

To mitigate this vulnerability, European organizations should: 1) Immediately audit their WordPress installations to identify the presence of the Zen Sticky Social plugin, especially versions up to 0.3. 2) Disable or remove the plugin until a security patch or update is released by the vendor. 3) Implement strict administrative access controls and limit the number of users with plugin configuration privileges to reduce the risk of exploitation. 4) Educate administrators about the risks of clicking on unsolicited or suspicious links, emphasizing the threat of CSRF and social engineering. 5) Employ Web Application Firewalls (WAFs) with rules to detect and block suspicious POST requests targeting the vulnerable plugin endpoints. 6) Monitor logs for unusual administrative actions or configuration changes that could indicate exploitation attempts. 7) Once a patch is available, promptly apply it and verify nonce validation is correctly implemented. 8) Consider implementing Content Security Policy (CSP) headers to mitigate the impact of injected scripts. These steps go beyond generic advice by focusing on plugin-specific detection, administrative behavior, and layered defenses tailored to the nature of the vulnerability.