CVE-2021-36368
OpenSSH FIDO Authentication Confusion Vulnerability
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.
INFO
Published Date :
March 13, 2022, 12:15 a.m.
Last Modified :
Aug. 4, 2024, 1:15 a.m.
Source :
[email protected]
Remotely Exploitable :
Yes !
Impact Score :
1.4
Exploitability Score :
2.2
Public PoC/Exploit Available at Github
CVE-2021-36368 has a 11 public PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-36368.
| URL | 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 |
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
DockerLab - Machine
Máquina DockerLab
None
Shell Roff Python
None
Shell Roff Python
Nmap's XML result parse and NVD's CPE correlation to search CVE.
Python
None
Roff Python
Walkthrough and Writeups for the HackTheBox Penetration Lab Testing Environment
None
Python
None
Python
None
SSH-MITM - ssh audits made simple
ssh ssh-server ssh-client mitmproxy mitm-server mitm-attacks security-audit security-tools mitm proxy ssh-mitm sftp scp security
Python Roff Shell
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-36368 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-36368 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
Aug. 04, 2024
Action Type Old Value New Value -
CVE Modified by [email protected]
May. 17, 2024
Action Type Old Value New Value -
CVE Modified by [email protected]
May. 14, 2024
Action Type Old Value New Value -
CVE Modified by [email protected]
Apr. 11, 2024
Action Type Old Value New Value -
CVE Modified by [email protected]
Mar. 21, 2024
Action Type Old Value New Value Added Tag MITRE disputed -
CVE Modified by [email protected]
Nov. 07, 2023
Action Type Old Value New Value Changed Description ** 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." 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. -
Modified Analysis by [email protected]
Jul. 01, 2022
Action Type Old Value New Value Changed Reference Type https://security-tracker.debian.org/tracker/CVE-2021-36368 No Types Assigned https://security-tracker.debian.org/tracker/CVE-2021-36368 Third Party Advisory Added CPE Configuration OR *cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* *cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* *cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* -
CVE Modified by [email protected]
Apr. 12, 2022
Action Type Old Value New Value Added Reference https://security-tracker.debian.org/tracker/CVE-2021-36368 [No Types Assigned] -
Initial Analysis by [email protected]
Mar. 20, 2022
Action Type Old Value New Value Added CVSS V2 NIST (AV:N/AC:H/Au:N/C:P/I:N/A:N) Added CVSS V3.1 NIST AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N Changed Reference Type https://bugzilla.mindrot.org/show_bug.cgi?id=3316 No Types Assigned https://bugzilla.mindrot.org/show_bug.cgi?id=3316 Issue Tracking, Third Party Advisory Changed Reference Type https://docs.ssh-mitm.at/trivialauth.html No Types Assigned https://docs.ssh-mitm.at/trivialauth.html Third Party Advisory Changed Reference Type https://github.com/openssh/openssh-portable/pull/258 No Types Assigned https://github.com/openssh/openssh-portable/pull/258 Patch, Third Party Advisory Changed Reference Type https://www.openssh.com/security.html No Types Assigned https://www.openssh.com/security.html Vendor Advisory Added CWE NIST CWE-287 Added CPE Configuration OR *cpe:2.3:a:openbsd:openssh:*:*:*:*:*:*:*:* versions up to (excluding) 8.9
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-36368 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-36368
weaknesses.
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
0.41 }} 0.20%
score
0.73687
percentile