CVE-2025-46215 is an Improper Isolation or Compartmentalization vulnerability (CWE-653) affecting multiple versions of Fortinet FortiSandbox, specifically versions 5.0.0 through 5.0.1, 4.4.0 through 4.4.7, 4.2.x, and 4.0.x. FortiSandbox is a security product designed to analyze suspicious files and detect malware by executing them in a controlled sandbox environment. The vulnerability allows an unauthenticated attacker to submit specially crafted files that can evade the sandbox scanning process. This evasion occurs due to improper compartmentalization within the sandbox, enabling unauthorized code or command execution outside the intended isolated environment. The CVSS 3.1 base score is 5.0 (medium), with vector AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:P/RL:X/RC:C, indicating network attack vector, low attack complexity, no privileges or user interaction required, unchanged scope, no confidentiality or availability impact, but integrity impact present, and a proof-of-concept exploit exists though no known exploits are in the wild yet. The vulnerability could allow attackers to bypass malware detection mechanisms, potentially leading to undetected malicious activity within protected networks. FortiSandbox is widely deployed in enterprise and critical infrastructure environments to enhance threat detection capabilities, making this vulnerability significant for organizations relying on it for security.

For European organizations, the primary impact of CVE-2025-46215 is the potential bypass of malware detection and sandboxing defenses, which undermines the integrity of security operations. Attackers exploiting this vulnerability can submit malicious files that are not properly analyzed or contained, increasing the risk of malware infiltration and lateral movement within networks. This can lead to prolonged undetected compromises, data manipulation, or preparation for further attacks. While confidentiality and availability are not directly impacted by this vulnerability, the erosion of trust in sandbox results can degrade overall security posture. Organizations in sectors such as finance, government, healthcare, and critical infrastructure that rely heavily on FortiSandbox for threat detection are particularly vulnerable. The lack of authentication requirement and user interaction lowers the barrier for exploitation, increasing risk. Additionally, the vulnerability could be leveraged as part of multi-stage attacks targeting European entities, especially those with high Fortinet product adoption.

1. Immediate mitigation should focus on upgrading FortiSandbox to the latest patched versions once Fortinet releases security updates addressing CVE-2025-46215. 2. Until patches are available, implement strict file submission policies to limit exposure to untrusted or suspicious files, including enhanced filtering and validation at network ingress points. 3. Employ network segmentation to isolate FortiSandbox systems from general user networks, reducing the attack surface. 4. Monitor FortiSandbox logs and network traffic for anomalies indicative of sandbox evasion attempts or unusual file submissions. 5. Deploy complementary security controls such as endpoint detection and response (EDR) and intrusion detection systems (IDS) to detect malicious activity that may bypass sandboxing. 6. Conduct regular vulnerability scanning and penetration testing focused on FortiSandbox environments to identify potential exploitation attempts. 7. Educate security teams about this vulnerability and update incident response plans to include detection and containment strategies for sandbox evasion techniques. 8. Coordinate with Fortinet support for guidance and timely information on patches and mitigation best practices.