CVE-2025-32766 is a stack-based buffer overflow vulnerability identified in Fortinet's FortiWeb product, specifically affecting CLI versions 7.6.0 through 7.6.3 and versions prior to 7.4.8. This vulnerability arises due to improper handling of input in the command-line interface, allowing a privileged attacker to craft malicious CLI commands that overflow the stack buffer. The overflow can lead to arbitrary code execution or command execution with the privileges of the CLI user, which typically requires high-level privileges. The vulnerability is classified under CWE-121, indicating a classic stack-based buffer overflow scenario. The CVSS v3.1 base score is 6.3, reflecting a medium severity level. The vector string (CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:F/RL:X/RC:C) indicates that the attack requires local access (AV:L), high attack complexity (AC:H), and high privileges (PR:H), with no user interaction (UI:N). The impact on confidentiality, integrity, and availability is high, and the exploitability is functional (E:F). No known exploits are currently reported in the wild. The vulnerability affects critical security infrastructure as FortiWeb is a web application firewall (WAF) used to protect web applications from attacks. Successful exploitation could allow attackers to bypass protections, execute arbitrary commands, and potentially compromise the underlying system or network environment.

For European organizations, this vulnerability poses a significant risk, especially for those relying on FortiWeb appliances to secure their web applications and critical infrastructure. Exploitation could lead to unauthorized command execution, resulting in data breaches, service disruptions, or lateral movement within networks. Given the high impact on confidentiality, integrity, and availability, attackers could exfiltrate sensitive data, modify or destroy data, or disrupt web services. The requirement for local access and high privileges limits the attack surface but does not eliminate risk, as insider threats or attackers who have already gained partial access could leverage this vulnerability to escalate privileges and compromise systems further. In sectors such as finance, healthcare, government, and critical infrastructure, where FortiWeb is commonly deployed, the consequences could be severe, including regulatory penalties under GDPR for data breaches and operational downtime affecting service delivery.

To mitigate this vulnerability, European organizations should prioritize the following actions: 1) Apply vendor-provided patches or updates as soon as they become available, ensuring that FortiWeb versions are upgraded beyond the affected versions (7.6.3 and 7.4.8). 2) Restrict CLI access strictly to trusted administrators and enforce strong authentication mechanisms, including multi-factor authentication, to prevent unauthorized local access. 3) Implement network segmentation and access controls to limit who can reach FortiWeb management interfaces, reducing the risk of local privilege exploitation. 4) Monitor logs and system behavior for unusual CLI command activity or signs of exploitation attempts. 5) Conduct regular security audits and vulnerability assessments on FortiWeb appliances to detect misconfigurations or outdated software. 6) Educate administrators on secure CLI usage and the risks of executing untrusted commands. 7) Employ intrusion detection/prevention systems (IDS/IPS) to detect anomalous traffic patterns that may indicate exploitation attempts. These measures, combined with timely patching, will significantly reduce the risk posed by this vulnerability.