Privilege escalation in FortiClient for Windows

1) Path traversal

EUVDB-ID: #VU64936

Risk: Low

CVSSv3.1: 7.7 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-41031

CWE-ID: CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to input validation error when processing directory traversal sequences in file names. A local user can execute arbitrary code with SYSTEM privileges via the named pipe responsible for FortiESNAC service.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Fortinet FortiClient for Windows: 6.2.0 - 7.0.2

External links

http://fortiguard.fortinet.com/psirt/FG-IR-21-190

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.