MitM attack in FortiOS Fortilink

1) Improper Certificate Validation

EUVDB-ID: #VU86280

Risk: Medium

CVSSv4.0: 1.7 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2023-47537

CWE-ID: CWE-295 - Improper Certificate Validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform MitM attack.

The vulnerability exists due to improper certificate validation in Fortilink. A remote attacker in a Man-in-the-Middle position can decipher and alter the FortiLink communication channel between the FortiOS device and a FortiSwitch instance.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

FortiOS: 7.0.0 - 7.4.1

CPE2.3

• cpe:2.3:o:fortinet:fortios:7.0.0:*:*:*:*:*:*:*
• cpe:2.3:o:fortinet:fortios:7.0.1:*:*:*:*:*:*:*
• cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*
• cpe:2.3:o:fortinet:fortios:7.0.3:*:*:*:*:*:*:*
• cpe:2.3:o:fortinet:fortios:7.0.4:*:*:*:*:*:*:*
• cpe:2.3:o:fortinet:fortios:7.0.5:*:*:*:*:*:*:*
• cpe:2.3:o:fortinet:fortios:7.0.6:*:*:*:*:*:*:*
• cpe:2.3:o:fortinet:fortios:7.0.7:*:*:*:*:*:*:*
• cpe:2.3:o:fortinet:fortios:7.0.8:*:*:*:*:*:*:*
• cpe:2.3:o:fortinet:fortios:7.0.9:*:*:*:*:*:*:*

External links

https://www.fortiguard.com/psirt/FG-IR-23-301

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

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