CVE-2021-36369: High severity dropbear ssh vulnerability

Published Oct 12, 2022
·
Updated

An issue was discovered in Dropbear through 2020.81. Due to a non-RFC-compliant check of the available authentication methods in the client-side SSH code, it is possible for an SSH server to change the login process in its favor. This attack can bypass additional security measures such as FIDO2 tokens or SSH-Askpass. Thus, it allows an attacker to abuse a forwarded agent for logging on to another server unnoticed.

Affected Software

3 affected componentsFixes available
debian/dropbear
2020.81-3+deb11u22022.83-1+deb12u22025.87-1
Dropbear Ssh Project Dropbear Ssh<=2020.81
Debian Debian Linux=10.0

Event History

Oct 12, 2022
CVE Published
via MITRE·12:00 AM
Data Sourced
via MITRE·12:00 AM
Description
Feb 25, 2025
Data Sourced
via Launchpad·04:59 PM
Description
Mar 1, 2025
Data Sourced
via Ubuntu·04:59 PM
RemedyDescriptionSeverityAffected Software
Mar 25, 2025
Data Sourced
via Debian·05:05 PM
DescriptionAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2021-36369?

CVE-2021-36369 is considered to have a medium severity due to its potential to bypass authentication in SSH sessions.

2

How do I fix CVE-2021-36369?

To mitigate CVE-2021-36369, update Dropbear SSH to version 2022.82 or later.

3

Which versions of Dropbear SSH are affected by CVE-2021-36369?

Dropbear SSH versions up to and including 2020.81 are affected by CVE-2021-36369.

4

What kind of systems are impacted by CVE-2021-36369?

CVE-2021-36369 affects systems using Dropbear SSH, particularly versions prior to 2022.82 and Debian GNU/Linux version 10.0.

5

What does CVE-2021-36369 exploit in Dropbear SSH?

CVE-2021-36369 exploits a non-RFC-compliant validation of authentication methods in the client-side SSH code.

Contact

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