CVE-2022-35843: 
FortiOS vulnerability analysis and mitigation

CVE-2022-35843 is an authentication bypass vulnerability discovered in the FortiOS SSH login component. The vulnerability was disclosed on December 6, 2022, with a CVSS v3.1 base score of 7.7 (High severity). It affects multiple versions of FortiOS (7.2.0, 7.0.0-7.0.7, 6.4.0-6.4.9, 6.2, and 6.0) and FortiProxy (7.0.0-7.0.5, 2.0.0-2.0.10, and 1.2.0) (Fortiguard Advisory, NVD).

The vulnerability is classified as an authentication bypass by assumed-immutable data vulnerability (CWE-302) in the SSH login component when RADIUS authentication is used. The CVSS v3.1 vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H, indicating network accessibility, low attack complexity, and no required privileges or user interaction (NVD).

The vulnerability allows a remote and unauthenticated attacker to login into the affected device by sending specially crafted Access-Challenge responses from the RADIUS server. This could lead to complete system compromise with high impacts on confidentiality, integrity, and availability (Fortiguard Advisory).

Fortinet has released patches to address this vulnerability. Users are advised to upgrade to FortiOS versions 7.2.2, 7.0.8, 6.4.10, or 6.2.13 and above, and FortiProxy versions 7.0.7 or 2.0.11 and above (Fortiguard Advisory).

The vulnerability was responsibly disclosed by Egbert Nijmeijer from ICT Teamwork. US government agencies have issued multiple alerts regarding FortiOS vulnerabilities, emphasizing the importance of timely patch application for federal agencies and private organizations (SecurityWeek).