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 (4)
Core 4
Core References
Mailing List, Third Party Advisory mailing-list
https://lists.debian.org/debian-lts-announce/2022/11/msg00015.html
Third Party Advisory
https://github.com/mkj/dropbear/pull/128
Release Notes, Third Party Advisory
https://github.com/mkj/dropbear/releases
Release Notes, Third Party Advisory
https://github.com/mkj/dropbear/releases/tag/DROPBEAR_2022.82
Scores
CVSS v3
7.5
EPSS
0.0021
EPSS Percentile
43.3%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-287
Status
published
Products (2)
debian/debian_linux
10.0
dropbear_ssh_project/dropbear_ssh
< 2020.81
Published
Oct 12, 2022
Tracked Since
Feb 18, 2026