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.
References
| Link | Resource |
|---|---|
| https://bugzilla.mindrot.org/show_bug.cgi?id=3316 | Issue Tracking Third Party Advisory |
| https://docs.ssh-mitm.at/trivialauth.html | Third Party Advisory |
| https://github.com/openssh/openssh-portable/pull/258 | Patch Third Party Advisory |
| https://security-tracker.debian.org/tracker/CVE-2021-36368 | Third Party Advisory |
| https://www.openssh.com/security.html | Vendor Advisory |
Configurations
History
07 Nov 2023, 03:36
| Type | Values Removed | Values Added |
|---|---|---|
| Summary | 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. |
Information
Published : 2022-03-13 00:15
Updated : 2024-08-04 01:15
NVD link : CVE-2021-36368
Mitre link : CVE-2021-36368
CVE.ORG link : CVE-2021-36368
JSON object : View
Products Affected
debian
- debian_linux
openbsd
- openssh
CWE
CWE-287
Improper Authentication