Vulnerability identifier: #VU54848

Vulnerability risk: Medium

CVSSv3.1: 5.5 [CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-26088

CWE-ID: CWE-287

Exploitation vector: Local network

Exploit availability: No

Vulnerable software:
FortiOS
Operating systems & Components / Operating system

Vendor: Fortinet, Inc

Description

The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to an error in FSSO Collector when processing authentication requests. A remote attacker can send specifically crafted UDP login notification packets to bypass any firewall authentication rule and access the protected network.

The vulnerability affects both the FSSO DC Agent and Collector.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

FortiOS: 7.0.0, 6.4.0 - 6.4.5, 6.0.0 - 6.0.12, 6.2.0 - 6.2.7

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External links
http://fortiguard.com/advisory/FG-IR-20-191

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

Is there known malware, which exploits this vulnerability?

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