CVE-2025-6675 is an authentication bypass vulnerability classified under CWE-288 (Authentication Bypass Using an Alternate Path or Channel) affecting the Enterprise MFA - TFA module for Drupal. This module is designed to provide multi-factor authentication (MFA) capabilities to Drupal-based websites, enhancing security by requiring additional verification beyond just a password. The vulnerability allows an attacker to bypass the authentication mechanism by exploiting an alternate path or channel within the MFA implementation, effectively circumventing the intended second-factor verification process. The affected versions include all releases before 4.8.0, versions from 5.2.0 before 5.2.1, and all versions before 5.0.* and 5.1.*. The flaw arises due to improper validation or control over authentication flows, enabling attackers to gain unauthorized access without completing the MFA challenge. Although no known exploits are currently reported in the wild, the vulnerability poses a significant risk because it undermines the core security benefit of MFA, potentially allowing attackers to impersonate legitimate users and access sensitive resources. The lack of a CVSS score indicates that the vulnerability is newly disclosed and has not yet been fully assessed for severity, but the nature of authentication bypass in a critical security module suggests a high-risk scenario.

For European organizations, this vulnerability could have severe consequences. Drupal is widely used across Europe for government portals, educational institutions, and private sector websites due to its flexibility and open-source nature. The Enterprise MFA - TFA module is often deployed to secure sensitive user accounts and administrative access. Exploitation of this vulnerability would allow attackers to bypass MFA protections, leading to unauthorized access to confidential data, manipulation of website content, or control over administrative functions. This could result in data breaches, defacement of public-facing websites, disruption of services, and loss of trust. Given the stringent data protection regulations in Europe, such as GDPR, organizations could face significant legal and financial repercussions if this vulnerability is exploited. Furthermore, the bypass could facilitate lateral movement within networks, increasing the risk of broader compromise.

Organizations using the Enterprise MFA - TFA module for Drupal should urgently update to the fixed versions: 4.8.0 or later, 5.2.1 or later, and any versions 5.0.* or 5.1.* that include the patch once released. Until patches are applied, administrators should consider temporarily disabling the MFA module to prevent exploitation, while balancing the risk of reduced authentication security. Additionally, organizations should implement compensating controls such as enhanced monitoring of authentication logs for suspicious activity, enforcing strong password policies, and restricting administrative access via IP whitelisting or VPNs. Conducting thorough audits of user access and MFA configurations can help identify potential misconfigurations that might be exploited. Finally, organizations should prepare incident response plans specifically addressing potential authentication bypass scenarios to quickly detect and respond to any exploitation attempts.