When traffic other than HTTP/S (eg: SSH traffic, etc ) traverses the FortiGate in version below 6.2.5 and below 6.4.2 on port 80/443, it is not redirected to the transparent proxy policy for processing, as it doesn’t have a valid HTTP header.
Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-15938
Reference (s):
- https://fortiguard.com/advisory/FG-IR-20-172
- URL: https://fortiguard.com/advisory/FG-IR-20-172

