Vulnerability Monitor

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CVE-2021-36368

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.

Security Impact Summary

This vulnerability carries a LOW severity rating with a CVSS v3.1 score of 3.7, indicating it can be exploited remotely over the network but requires specific conditions to be met without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts limited data confidentiality, for affected systems. Impacting 2 products from openbsd, from debian organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2022, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.

Published

2022-03-13T00:15:07.937

Last Modified

2024-11-21T06:13:36.983

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 3.7 (LOW)

CVSSv2 Vector

AV:N/AC:H/Au:N/C:P/I:N/A:N

Access Vector: NETWORK
Access Complexity: HIGH
Authentication: NONE
Confidentiality Impact: PARTIAL
Integrity Impact: NONE
Availability Impact: NONE

Exploitability Score

4.9

Impact Score

2.9

Weaknesses

Type: Primary
CWE-287

Affected Vendors & Products

Type	Vendor	Product	Version/Range	Vulnerable?
Application	openbsd	openssh	< 8.9	Yes
Operating System	debian	debian_linux	9.0	Yes
Operating System	debian	debian_linux	10.0	Yes
Operating System	debian	debian_linux	11.0	Yes

References

https://bugzilla.mindrot.org/show_bug.cgi?id=3316 Issue Tracking, Third Party Advisory ([email protected])
https://docs.ssh-mitm.at/trivialauth.html Third Party Advisory ([email protected])
https://github.com/openssh/openssh-portable/pull/258 Patch, Third Party Advisory ([email protected])
https://security-tracker.debian.org/tracker/CVE-2021-36368 Third Party Advisory ([email protected])
https://www.openssh.com/security.html Vendor Advisory ([email protected])
https://bugzilla.mindrot.org/show_bug.cgi?id=3316 Issue Tracking, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://docs.ssh-mitm.at/trivialauth.html Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://github.com/openssh/openssh-portable/pull/258 Patch, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://security-tracker.debian.org/tracker/CVE-2021-36368 Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://www.openssh.com/security.html Vendor Advisory (af854a3a-2127-422b-91ae-364da2661108)

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For openbsd's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.