Bug 2086690 (CVE-2021-36368)

Summary:	CVE-2021-36368 openssh: possible bypass of fido 2 devices and ssh-askpass
Product:	[Other] Security Response	Reporter:	TEJ RATHI <trathi>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	unspecified	CC:	bdettelb, crypto-team, dbelyavs, dwalsh, jburrell, jjelen, lkundrak, mattias.ellert, tm, vkumar
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
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Fixed In Version:		Doc Type:	If docs needed, set a value
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Last Closed:	2022-05-16 13:19:11 UTC	Type:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	2086696

Description TEJ RATHI 2022-05-16 13:18:57 UTC

** 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 "this is not an authentication bypass, since nothing is being bypassed."

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