CVE-2025-5392 is a critical remote code execution (RCE) vulnerability affecting the GB Forms DB plugin for WordPress, specifically all versions up to and including 1.0.2. The vulnerability arises from improper control of code generation (CWE-94) within the gbfdb_talk_to_front() function. This function accepts user input and directly passes it to PHP's call_user_func() without adequate validation or sanitization. As a result, unauthenticated attackers can craft malicious input that leads to arbitrary code execution on the server hosting the vulnerable plugin. Exploiting this flaw allows attackers to execute arbitrary PHP code remotely, which can be leveraged to inject persistent backdoors, create new administrative user accounts, or perform other malicious activities that compromise the confidentiality, integrity, and availability of the affected system. The vulnerability has a CVSS 3.1 base score of 9.8, indicating a critical severity with network attack vector, no required privileges, and no user interaction needed. Although no public exploits have been reported in the wild yet, the ease of exploitation and the impact potential make this a highly dangerous vulnerability for WordPress sites using GB Forms DB. Given the widespread use of WordPress in Europe and the plugin's role in managing form data, this vulnerability poses a significant risk to websites relying on this plugin for data collection and user interaction.

For European organizations, the impact of CVE-2025-5392 can be severe. Many businesses, governmental agencies, and non-profits in Europe rely on WordPress for their web presence, including forms for customer interaction, data collection, and internal workflows. Exploitation of this vulnerability could lead to full server compromise, data breaches involving sensitive personal or corporate data, defacement of websites, and disruption of services. This could result in regulatory non-compliance issues under GDPR due to unauthorized data access or leakage, leading to heavy fines and reputational damage. Additionally, attackers could use compromised servers as pivot points for lateral movement within organizational networks or as part of larger botnets or ransomware campaigns. The lack of authentication and user interaction requirements means that attackers can remotely exploit this vulnerability at scale, increasing the likelihood of widespread attacks targeting European entities.

Immediate mitigation involves updating the GB Forms DB plugin to a patched version once released by the vendor. Since no patch links are currently available, organizations should implement temporary workarounds such as disabling or removing the GB Forms DB plugin until a fix is provided. Web application firewalls (WAFs) should be configured to detect and block suspicious requests targeting the gbfdb_talk_to_front() function or containing unusual call_user_func() payloads. Organizations should also conduct thorough audits of their WordPress installations to identify the presence of this plugin and monitor logs for any signs of exploitation attempts. Restricting PHP function calls and disabling dangerous PHP functions like call_user_func() where feasible can reduce the attack surface. Regular backups and incident response plans should be reviewed and tested to prepare for potential compromise. Finally, organizations should implement strict input validation and sanitization practices in custom code to prevent similar vulnerabilities.