CVE-2016-20012

Name	CVE-2016-20012
Description	DISPUTED OpenSSH through 8.7 allows remote attackers, who have a suspicion that a certain combination of username and public key is known to an SSH server, to test whether this suspicion is correct. This occurs because a challenge is sent only when that combination could be valid for a login session. NOTE: the vendor does not recognize user enumeration as a vulnerability for this product.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
openssh (PTS)	stretch	1:7.4p1-10+deb9u7	vulnerable
	stretch (security)	1:7.4p1-10+deb9u6	vulnerable
	buster	1:7.9p1-10+deb10u2	vulnerable
	buster (security)	1:7.9p1-10+deb10u1	vulnerable
	bullseye	1:8.4p1-5	vulnerable
	bookworm, sid	1:9.0p1-1	vulnerable

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
openssh	source	(unstable)	(unfixed)	unimportant

https://github.com/openssh/openssh-portable/pull/270
Negligible impact, not treated as a security issue by upstream