CVE-2021-36368 Information
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DISPUTED 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 his is not an authentication bypass since nothing is being bypassed.\
CVSS Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Reference
https://github.com/openssh/openssh-portable/pull/258 https://docs.ssh-mitm.at/trivialauth.html https://bugzilla.mindrot.org/show_bug.cgi?id=3316 https://www.openssh.com/security.html https://security-tracker.debian.org/tracker/CVE-2021-36368
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction Required
NONE
Scope
NONE
Confidentiality Impact
UNCHANGED
Integrity Impact
LOW
Availability Impact
NONE
Base Score
NONE
Base Severity
3.7