CVE-2025-64153 is an OS command injection vulnerability affecting Fortinet FortiExtender devices running versions 7.0.0 through 7.6.3. The flaw arises from improper neutralization of special characters in operating system commands processed by the device's HTTP interface. An attacker with authenticated access and high privileges can craft a specific HTTP request that injects malicious OS commands, leading to unauthorized code execution. This can result in full compromise of the device, allowing attackers to manipulate device configurations, intercept or disrupt network traffic, or pivot to other internal systems. The vulnerability does not require user interaction but does require authentication, limiting exploitation to insiders or attackers who have obtained valid credentials. The CVSS v3.1 score is 6.7 (medium severity), reflecting the network attack vector, low attack complexity, high privileges required, and significant impact on confidentiality, integrity, and availability. No public exploits or active exploitation have been reported to date. FortiExtender devices are commonly used to extend network connectivity, often in critical infrastructure or enterprise environments, making this vulnerability a significant risk if left unpatched.

For European organizations, exploitation of CVE-2025-64153 could lead to unauthorized control over FortiExtender devices, compromising network extension points. This may result in data breaches, interception of sensitive communications, disruption of network services, and potential lateral movement within corporate or critical infrastructure networks. Given FortiExtender's role in providing cellular WAN connectivity and network extension, attackers could disrupt business continuity or gain footholds for further attacks. The requirement for authenticated access reduces the risk from external attackers but raises concerns about insider threats or credential compromise. Organizations in sectors such as telecommunications, energy, finance, and government, which rely heavily on Fortinet products for secure connectivity, may face elevated risks. The absence of known exploits currently provides a window for mitigation, but the potential impact on confidentiality, integrity, and availability is significant if exploited.

1. Apply vendor-provided patches immediately once available to address the vulnerability. 2. Restrict administrative access to FortiExtender devices using network segmentation, VPNs, and IP whitelisting to limit exposure. 3. Enforce strong authentication mechanisms, including multi-factor authentication, to reduce risk of credential compromise. 4. Monitor HTTP request logs and network traffic for anomalous patterns indicative of command injection attempts. 5. Conduct regular audits of user accounts and privileges on FortiExtender devices to detect unauthorized access. 6. Implement strict change management and configuration backup procedures to quickly restore devices if compromised. 7. Educate administrators about the risks of credential theft and the importance of secure password practices. 8. Consider deploying intrusion detection/prevention systems tailored to detect exploitation attempts targeting FortiExtender HTTP interfaces.