CVE-2024-27779 is a vulnerability classified under improper access control due to insufficient session expiration (CWE-613) in Fortinet's FortiSandbox and FortiIsolator products. The flaw exists in versions 4.4.4 and below for FortiSandbox and 2.4 and below for FortiIsolator, across multiple major releases. The vulnerability allows a remote attacker who has obtained an administrative session cookie to continue using that session even after the corresponding admin user account has been deleted from the system. This occurs because the session tokens are not invalidated or expired properly upon user deletion, allowing persistent unauthorized access. The attack vector is network-based (AV:N), requires low attack complexity (AC:L), but requires high privileges (PR:H) since possession of an admin session cookie is necessary. No user interaction is required (UI:N). The impact on confidentiality and integrity is high (C:H/I:H) because an attacker can maintain administrative control, potentially accessing sensitive data and modifying configurations. The availability impact is low (A:L). The vulnerability is exploitable remotely and could allow attackers to maintain persistent access to critical security infrastructure, undermining trust in sandboxing and isolation mechanisms. No known exploits are reported in the wild yet, but the risk remains significant due to the nature of the affected products. Fortinet has published the vulnerability with a CVSS score of 6.3, indicating medium severity. The lack of immediate patches necessitates interim mitigations focused on session management and monitoring.

For European organizations, especially those in sectors relying on Fortinet FortiSandbox and FortiIsolator for advanced threat detection and network isolation, this vulnerability poses a significant risk. Unauthorized persistent administrative access could lead to data breaches, manipulation of sandbox analysis results, and potential lateral movement within networks. This undermines the security posture by allowing attackers to bypass user deletion controls and maintain footholds in critical security infrastructure. The confidentiality and integrity of sensitive data and security policies are at risk, potentially impacting compliance with GDPR and other regulatory frameworks. The availability impact is limited but could escalate if attackers modify configurations or disable security features. Organizations in finance, government, healthcare, and critical infrastructure sectors are particularly vulnerable due to their reliance on Fortinet products for threat mitigation and network segmentation.

1. Apply vendor patches immediately once released to address the session expiration flaw. 2. Implement strict session management policies, including reducing session timeout durations and enforcing session invalidation upon user deletion or privilege changes. 3. Monitor administrative session activity closely for anomalies, such as sessions persisting beyond user deletion events or unusual access patterns. 4. Restrict administrative access to FortiSandbox and FortiIsolator interfaces using network segmentation, VPNs, and IP whitelisting to reduce exposure. 5. Employ multi-factor authentication (MFA) for all administrative accounts to reduce the risk of session cookie theft. 6. Regularly audit user accounts and session logs to detect and respond to unauthorized access promptly. 7. Consider deploying endpoint detection and response (EDR) solutions to identify suspicious activities related to session misuse. 8. Educate administrators on secure session handling and the importance of logging out and clearing sessions after use.