CVE-2025-53679 is a remote OS command injection vulnerability affecting Fortinet FortiSandbox Cloud versions 24.1 and 23.4, as well as earlier versions 5.0.0 through 5.0.2 and before 4.4.7 GUI. The vulnerability stems from improper neutralization of special elements used in OS commands (CWE-78), allowing a remote attacker with privileged access to execute arbitrary commands on the underlying operating system. Exploitation occurs via crafted HTTP or HTTPS requests sent to the FortiSandbox Cloud GUI interface, which fails to properly sanitize input before passing it to OS commands. This can lead to unauthorized code execution, potentially compromising the confidentiality, integrity, and availability of the affected system. The CVSS 3.1 base score is 6.9, reflecting a medium severity level, primarily because exploitation requires high privileges (PR:H) and no user interaction (UI:N). The vulnerability is network exploitable (AV:N) and affects the entire scope of the vulnerable system (S:U). No known exploits have been reported in the wild as of the publication date. FortiSandbox Cloud is widely used for advanced threat detection and sandboxing in enterprise environments, making this vulnerability significant for organizations relying on Fortinet’s security ecosystem. The improper input validation in the GUI component highlights a critical security oversight that could allow attackers to bypass intended access controls and execute arbitrary commands remotely. Fortinet has not yet published patches or mitigation details at the time of this report, but organizations should prepare to apply updates once available and implement compensating controls to limit exposure.

The impact of CVE-2025-53679 on European organizations could be substantial, especially for those relying on FortiSandbox Cloud for malware analysis and threat detection. Successful exploitation allows attackers to execute arbitrary OS commands remotely with high privileges, potentially leading to full system compromise. This can result in data breaches, disruption of security monitoring capabilities, lateral movement within networks, and potential sabotage of critical infrastructure. Confidentiality is at high risk due to unauthorized access to sensitive data processed by FortiSandbox. Integrity and availability are also severely impacted as attackers could alter or disable security functions, degrade system performance, or cause denial of service. European sectors such as finance, energy, telecommunications, and government agencies that utilize Fortinet products for cybersecurity defenses are particularly vulnerable. The medium CVSS score reflects the need for privileged access, which somewhat limits the attack surface, but insider threats or compromised credentials could facilitate exploitation. The absence of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, especially as attackers often develop exploits rapidly after vulnerability disclosure. Organizations in Europe must consider the potential for targeted attacks leveraging this vulnerability to disrupt critical services or exfiltrate sensitive information.

1. Apply patches and updates from Fortinet immediately once they are released for FortiSandbox Cloud versions 24.1, 23.4, and earlier affected versions. 2. Restrict administrative access to the FortiSandbox GUI interface by implementing strict network segmentation and firewall rules limiting access to trusted IP addresses only. 3. Enforce strong authentication mechanisms for privileged accounts, including multi-factor authentication (MFA), to reduce the risk of credential compromise. 4. Monitor HTTP and HTTPS traffic to the FortiSandbox GUI for anomalous or suspicious requests that may indicate exploitation attempts, using intrusion detection/prevention systems (IDS/IPS) and security information and event management (SIEM) tools. 5. Conduct regular audits of user privileges and remove unnecessary administrative rights to minimize the number of accounts capable of exploiting this vulnerability. 6. Implement application-layer filtering or web application firewalls (WAF) to detect and block injection attempts targeting the GUI. 7. Educate security teams about this vulnerability and update incident response plans to include potential exploitation scenarios. 8. Consider deploying network-level segmentation to isolate FortiSandbox systems from other critical infrastructure to limit lateral movement in case of compromise.