CVE-2025-24477 is a heap-based buffer overflow vulnerability identified in Fortinet's FortiOS firewall operating system, affecting versions 7.2.4 through 7.2.12, 7.4.0 through 7.4.7, and 7.6.0 through 7.6.2. The flaw arises from improper handling of input in the command-line interface (CLI), where a specially crafted command can overflow a heap buffer, leading to memory corruption. This corruption allows an attacker who already has some level of privilege on the device to escalate their privileges, potentially gaining full administrative control. The vulnerability requires local access with at least high privileges (PR:H), no user interaction is needed, and the attack scope is unchanged (S:U). The CVSS v3.1 base score is 4.0, reflecting limited impact on confidentiality, integrity, and availability, but with potential for privilege escalation. No public exploits or active exploitation have been reported yet, but the vulnerability is critical to address due to the sensitive nature of FortiOS devices in network security infrastructure. FortiOS is widely deployed in enterprise and service provider environments, making this vulnerability significant for network defense.

For European organizations, this vulnerability poses a risk primarily to the integrity and availability of network security infrastructure. Successful exploitation could allow attackers to gain elevated privileges on FortiOS devices, potentially enabling unauthorized configuration changes, disabling security controls, or disrupting network traffic. This could lead to data breaches, network outages, or lateral movement within corporate networks. Given Fortinet's strong presence in Europe, especially in sectors like finance, telecommunications, and critical infrastructure, the impact could be substantial if exploited. The requirement for existing high privileges limits the threat to insider attackers or those who have already compromised lower-level accounts, but the potential for privilege escalation makes it a serious concern for maintaining secure network perimeters.

Organizations should immediately identify and inventory all FortiOS devices running affected versions (7.2.4 through 7.2.12, 7.4.0 through 7.4.7, and 7.6.0 through 7.6.2). Although no patches are linked in the provided data, monitoring Fortinet advisories for official patches or updates is critical. In the interim, restrict CLI access strictly to trusted administrators and enforce strong authentication mechanisms such as multi-factor authentication. Implement network segmentation to limit access to management interfaces and monitor CLI command logs for suspicious activity. Employ strict role-based access controls to minimize the number of users with high privileges. Regularly audit user privileges and remove unnecessary access. Additionally, consider deploying intrusion detection systems that can detect anomalous CLI commands or buffer overflow attempts. Finally, maintain up-to-date backups of device configurations to enable rapid recovery if compromise occurs.