CVE-2025-34077 is a critical vulnerability affecting the WordPress Pie Register plugin versions up to 3.7.1.4 developed by Genetech Solutions. The flaw arises from an authentication bypass that allows unauthenticated attackers to impersonate arbitrary users by sending a specially crafted POST request to the plugin’s login endpoint. By setting the parameter social_site=true and manipulating user_id_social_site, attackers can generate valid WordPress session cookies for any user ID, including administrators, without needing credentials or prior authentication. This bypasses normal authentication mechanisms (CWE-306). Once authenticated as an arbitrary user, the attacker can exploit the plugin’s file upload functionality, which lacks proper restrictions on file types (CWE-434). This enables uploading of malicious plugins containing arbitrary PHP code (CWE-94), leading to remote code execution (RCE) on the underlying web server. The vulnerability’s CVSS 4.0 score is 10, indicating critical severity with network attack vector, no required privileges or user interaction, and high impact on confidentiality, integrity, and availability. Although no known exploits are currently in the wild, the combination of authentication bypass and unrestricted file upload makes this a highly exploitable and dangerous flaw. The vulnerability affects all versions of the plugin up to 3.7.1.4, and no official patches have been linked yet. Organizations running WordPress sites with this plugin are at risk of complete site takeover, data theft, defacement, or use of the server for further attacks.

For European organizations, the impact of CVE-2025-34077 is severe. Exploitation allows attackers to gain administrative access to WordPress sites without authentication, enabling full control over site content, user data, and backend systems. This can lead to data breaches involving personal and sensitive information, violating GDPR and other data protection regulations, resulting in legal and financial penalties. Remote code execution on the web server can facilitate deployment of backdoors, ransomware, or pivoting to internal networks, threatening broader enterprise infrastructure. E-commerce, government, healthcare, and media sectors in Europe that rely on WordPress with this plugin are particularly vulnerable to service disruption, reputational damage, and operational downtime. The ease of exploitation and lack of required user interaction increase the likelihood of automated attacks targeting vulnerable sites. Given the criticality, European organizations must prioritize detection and remediation to prevent potential large-scale compromise and compliance violations.

Immediate mitigation steps include disabling or uninstalling the Pie Register plugin until a secure patch is released by Genetech Solutions. If disabling is not feasible, restrict access to the plugin’s endpoints via web application firewall (WAF) rules or IP whitelisting to block unauthenticated POST requests manipulating social_site and user_id_social_site parameters. Implement strict file upload validation on the server side, allowing only safe file types and scanning uploads for malicious content. Monitor WordPress logs for suspicious login attempts or unusual file uploads. Employ multi-factor authentication (MFA) for WordPress administrator accounts to reduce risk of session hijacking. Regularly update WordPress core and all plugins to the latest versions once patches become available. Conduct thorough security audits and penetration testing focused on plugin vulnerabilities. Backup website data and configurations frequently to enable recovery in case of compromise. Educate site administrators about this vulnerability and signs of exploitation. Consider deploying runtime application self-protection (RASP) tools to detect and block exploitation attempts in real time.