CVE-2021-36368

Name	CVE-2021-36368
Description	An issue was discovered in OpenSSH before 8.9. If a client is using public-key authentication with agent forwarding but without -oLogLevel=verbose, and an attacker has silently modified the server to support the None authentication option, then the user cannot determine whether FIDO authentication is going to confirm that the user wishes to connect to that server, or that the user wishes to allow that server to connect to a different server on the user's behalf. NOTE: the vendor's position is "this is not an authentication bypass, since nothing is being bypassed.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
openssh (PTS)	jessie, jessie (lts)	1:6.7p1-5+deb8u10	vulnerable
	stretch (security)	1:7.4p1-10+deb9u6	vulnerable
	stretch (lts), stretch	1:7.4p1-10+deb9u9	vulnerable
	buster	1:7.9p1-10+deb10u2	vulnerable
	buster (security)	1:7.9p1-10+deb10u4	vulnerable
	bullseye (security), bullseye	1:8.4p1-5+deb11u3	vulnerable
	bookworm (security), bookworm	1:9.2p1-2+deb12u2	fixed
	sid, trixie	1:9.7p1-4	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
openssh	source	(unstable)	1:8.9p1-1	unimportant

https://bugzilla.mindrot.org/show_bug.cgi?id=3316
https://docs.ssh-mitm.at/trivialauth.html