CVE-2025-31514 is an information disclosure vulnerability identified in Fortinet's FortiProxy product, affecting FortiOS versions 6.4 all versions, 7.0 all versions, 7.2 all versions, 7.4 all versions, and specifically 7.6.0 through 7.6.3. The root cause is the insertion of sensitive two-factor authentication (2FA) related information into log files, violating secure logging practices (CWE-532). An attacker with at least read-only privileges on the FortiProxy device can retrieve this sensitive information by accessing logs or executing diagnostic commands. The vulnerability does not require user interaction and is exploitable remotely with network access, but requires high privileges (read-only or above). The CVSS v3.1 base score is 2.6, reflecting low severity due to limited confidentiality impact and no effect on integrity or availability. No known exploits have been reported in the wild as of the publication date. The vulnerability could potentially aid attackers in bypassing 2FA protections or escalating privileges if combined with other attack vectors. FortiProxy is widely used in enterprise and service provider environments for secure web gateway and proxy services, making this vulnerability relevant for organizations relying on Fortinet products for network security and access control.

For European organizations, the primary impact is the potential exposure of sensitive 2FA-related information, which could weaken multi-factor authentication defenses and increase the risk of account compromise. Although the vulnerability requires read-only access, which is a higher privilege level, insider threats or attackers who have already gained limited access could leverage this to escalate attacks. The confidentiality breach could lead to unauthorized access to critical systems if attackers use the disclosed 2FA data to bypass authentication mechanisms. However, there is no direct impact on system integrity or availability, limiting the scope of damage. Organizations in sectors with stringent compliance requirements around authentication and data protection, such as finance, healthcare, and government, may face regulatory and reputational risks if this vulnerability is exploited. The absence of known exploits reduces immediate risk but does not eliminate the need for proactive mitigation.

1. Apply official patches or updates from Fortinet as soon as they become available to address this vulnerability. 2. Restrict read-only access to FortiProxy devices strictly to trusted administrators and monitor access logs for unusual activity. 3. Limit the use of diagnostic commands to authorized personnel only and audit their usage regularly. 4. Implement strict log management policies to ensure sensitive information is not stored in logs or is properly redacted. 5. Employ network segmentation and access controls to reduce the attack surface and prevent unauthorized access to FortiProxy management interfaces. 6. Conduct regular security assessments and penetration tests focusing on privilege escalation and information disclosure risks. 7. Educate administrators about the risks of exposing sensitive 2FA information and enforce the principle of least privilege. 8. Monitor threat intelligence feeds for any emerging exploits targeting this vulnerability.