CVE-2025-3627 is a security vulnerability identified in Moodle versions 4.3.0, 4.4.0, and 4.5.0. Moodle is a widely used open-source learning management system (LMS) deployed by educational institutions globally, including many in Europe. The vulnerability stems from improper authentication handling, specifically related to the two-factor authentication (2FA) process. In affected versions, certain users can access sensitive information about other students before completing the 2FA verification step. This means that the system fails to enforce full authentication rigorously, allowing unauthorized users to bypass the second factor and gain premature access to confidential student data. The sensitive information potentially exposed could include personal identifiers, academic records, grades, or other private details stored within the Moodle platform. Although no known exploits are currently reported in the wild, the flaw represents a significant risk due to the nature of the data involved and the widespread use of Moodle in academic environments. The vulnerability does not require advanced exploitation techniques but leverages a logical flaw in the authentication workflow. Since 2FA is intended to provide an additional security layer, bypassing it undermines the integrity of the authentication process and increases the risk of data leakage. The vulnerability was published on April 25, 2025, and is currently classified as medium severity by the source, but no official CVSS score has been assigned. No patches or fixes are linked yet, indicating that affected organizations need to be vigilant and consider interim protective measures.

For European organizations, particularly educational institutions such as universities, colleges, and training centers that rely on Moodle, this vulnerability poses a risk to the confidentiality and integrity of student data. Unauthorized access to sensitive student information can lead to privacy violations, regulatory non-compliance (e.g., GDPR breaches), reputational damage, and potential legal consequences. The exposure of personal data could also facilitate targeted phishing or social engineering attacks against students or staff. Since Moodle is often integrated with other academic and administrative systems, the compromise of user data could have cascading effects, potentially impacting broader institutional IT infrastructure. The improper authentication flaw undermines trust in the platform's security, which is critical for institutions managing sensitive academic records. While availability is not directly impacted, the breach of confidentiality and integrity is significant given the nature of the data. The risk is heightened in environments where 2FA is mandated as a security control, as the vulnerability effectively negates this protection for certain users.

1. Immediate mitigation should include disabling or restricting access to affected Moodle versions (4.3.0, 4.4.0, 4.5.0) until patches are available. 2. Implement additional access controls at the network or application layer, such as IP whitelisting or VPN requirements, to limit exposure. 3. Temporarily enforce stricter session management and monitoring to detect anomalous access patterns indicative of authentication bypass attempts. 4. Educate users and administrators about the vulnerability and encourage vigilance for suspicious activity. 5. If possible, configure Moodle to require full authentication before any sensitive information is displayed, potentially by adjusting authentication workflows or disabling partial access features. 6. Monitor official Moodle security advisories closely for patches or updates addressing this vulnerability and apply them promptly. 7. Conduct internal audits of user access logs to identify any unauthorized data access that may have occurred. 8. Consider deploying additional multi-factor authentication mechanisms external to Moodle to provide layered security. These steps go beyond generic advice by focusing on interim controls and monitoring tailored to the Moodle platform and the specific authentication weakness.