CVE-2021-36369

Publication date 12 October 2022

Last updated 26 February 2025


Ubuntu priority

Cvss 3 Severity Score

7.5 · High

Score breakdown

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.

Status

Package Ubuntu Release Status
dropbear 24.10 oracular
Fixed 2020.81-3+deb11u1
24.04 LTS noble
Fixed 2020.81-3+deb11u1
23.10 mantic Ignored end of life, was needs-triage
23.04 lunar Ignored end of life, was needs-triage
22.10 kinetic Ignored end of life, was needs-triage
22.04 LTS jammy
Fixed 2020.81-5ubuntu0.1
20.04 LTS focal
18.04 LTS bionic
16.04 LTS xenial
Vulnerable
14.04 LTS trusty Ignored end of standard support

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Severity score breakdown

Parameter Value
Base score 7.5 · High
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Scope Unchanged
Confidentiality None
Integrity impact High
Availability impact None
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N