CVE-2021-36369

high

Description

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.

References

https://lists.debian.org/debian-lts-announce/2022/11/msg00015.html

https://github.com/mkj/dropbear/releases/tag/DROPBEAR_2022.82

https://github.com/mkj/dropbear/releases

https://github.com/mkj/dropbear/pull/128

Details

Source: Mitre, NVD

Published: 2022-10-12

Updated: 2023-01-20

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:C/A:N

Severity: High

CVSS v3

Base Score: 7.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Severity: High