CVE-2024-40593 is a vulnerability stemming from improper access control and key management errors in Fortinet's FortiPortal 6.0.0 and several versions of FortiAnalyzer, FortiManager, and FortiOS. The flaw allows an authenticated administrator with high privileges to retrieve private keys associated with certificates by accessing the device's administrative shell. This vulnerability arises because the system does not adequately restrict access to sensitive cryptographic material, enabling disclosure of private keys that are critical for secure communications and device authentication. The affected versions include FortiAnalyzer 6.4 through 7.4.2, FortiManager 6.4 through 7.4.2, FortiOS 7.0.14 through 7.6.0, and FortiPortal 6.0.0. The CVSS 3.1 vector indicates that the attack requires local access (AV:L), low attack complexity (AC:L), high privileges (PR:H), no user interaction (UI:N), and results in a confidentiality impact (C:H) without affecting integrity or availability. The scope is changed (S:C), meaning the vulnerability affects components beyond the initially vulnerable component. No known exploits are currently reported in the wild, but the potential for misuse exists given the sensitivity of private keys. The vulnerability was published on December 11, 2025, with the reservation date in July 2024. The flaw can be leveraged to compromise the confidentiality of cryptographic keys, potentially enabling attackers to decrypt communications, impersonate devices, or perform man-in-the-middle attacks if keys are exfiltrated. This vulnerability highlights the importance of strict access controls around administrative interfaces and cryptographic key storage in network security appliances.

For European organizations, this vulnerability poses a significant risk to the confidentiality of cryptographic keys used in securing network communications and device authentication within Fortinet infrastructure. Organizations relying on Fortinet FortiPortal, FortiAnalyzer, FortiManager, or FortiOS for network security management or logging could have their private keys exposed if an attacker gains authenticated admin access. This exposure could lead to interception or decryption of sensitive data, unauthorized device impersonation, or lateral movement within networks. Critical sectors such as finance, government, telecommunications, and energy, which often deploy Fortinet products extensively, may face increased risks of espionage or disruption. The requirement for high privilege authentication limits the attack surface but insider threats or compromised admin credentials could enable exploitation. The lack of known exploits in the wild reduces immediate risk but does not eliminate the threat, especially given the strategic importance of Fortinet devices in European critical infrastructure. Failure to address this vulnerability could undermine trust in network security and compliance with data protection regulations such as GDPR if sensitive data confidentiality is compromised.

1. Apply official patches or updates from Fortinet as soon as they become available for all affected products and versions, including FortiPortal 6.0.0 and related FortiAnalyzer, FortiManager, and FortiOS versions. 2. Restrict administrative shell access strictly to trusted personnel and use multi-factor authentication (MFA) for all admin accounts to reduce the risk of credential compromise. 3. Regularly audit and monitor administrative access logs and shell command usage to detect any unauthorized attempts to access private keys or sensitive files. 4. Implement network segmentation to isolate management interfaces from general network access, limiting exposure to authenticated attackers. 5. Rotate and revoke certificates and private keys if there is any suspicion of compromise to prevent misuse. 6. Employ hardware security modules (HSMs) or secure key storage solutions where possible to protect private keys from extraction. 7. Conduct internal security awareness training emphasizing the importance of safeguarding admin credentials and recognizing suspicious activity. 8. Review and harden Fortinet device configurations to minimize unnecessary privileges and disable unused services. 9. Engage with Fortinet support or professional services for guidance on secure deployment and remediation strategies. 10. Maintain an incident response plan that includes procedures for handling private key compromise scenarios.