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.
NVD Severity
unknown
Other trackers
Mailing lists
Exploits
Forges
GitHub (code, issues), Aports (code, issues)

References

Type URI
MISC https://github.com/openssh/openssh-portable/pull/258
MISC https://docs.ssh-mitm.at/trivialauth.html
CONFIRM https://bugzilla.mindrot.org/show_bug.cgi?id=3316
MISC https://www.openssh.com/security.html
MISC https://security-tracker.debian.org/tracker/CVE-2021-36368

Match rules

CPE URI Source package Min version Max version
cpe:2.3:a:openbsd:openssh:*:*:*:*:*:*:*:* openssh >= None < 8.9

Vulnerable and fixed packages

Source package Branch Version Maintainer Status
openssh 3.15-main 8.8_p1-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
openssh 3.14-main 8.6_p1-r3 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
openssh 3.13-main 8.4_p1-r4 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
openssh 3.12-main 8.3_p1-r3 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable