CVE-2021-36368
Published: 13 March 2022
** 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."
Notes
| Author | Note |
|---|---|
| seth-arnold | openssh-ssh1 is provided for compatibility with old devices that cannot be upgraded to modern protocols. Thus we may not provide security support for this package if doing so would prevent access to equipment. |
| mdeslaur | This CVE appears to have been disputed by upstream, marking as not-affected |
Priority
Status
| Package | Release | Status |
|---|---|---|
|
openssh Launchpad, Ubuntu, Debian |
bionic |
Not vulnerable
|
| focal |
Not vulnerable
|
|
| impish |
Not vulnerable
|
|
| jammy |
Not vulnerable
|
|
| trusty |
Not vulnerable
|
|
| upstream |
Needs triage
|
|
| xenial |
Not vulnerable
|
|
|
openssh-ssh1 Launchpad, Ubuntu, Debian |
bionic |
Not vulnerable
|
| focal |
Not vulnerable
|
|
| impish |
Not vulnerable
|
|
| jammy |
Not vulnerable
|
|
| trusty |
Does not exist
|
|
| upstream |
Ignored
(frozen on openssh 7.5p)
|
|
| xenial |
Does not exist
|
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 3.7 |
| Attack vector | Network |
| Attack complexity | High |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | Low |
| Integrity impact | None |
| Availability impact | None |
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N |