Debian DLA-3187-1 : dropbear - LTS security update

high Nessus Plugin ID 167353

Synopsis

The remote Debian host is missing a security-related update.

Description

The remote Debian 10 host has packages installed that are affected by a vulnerability as referenced in the dla-3187 advisory.

- 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. (CVE-2021-36369)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Upgrade the dropbear packages.

For Debian 10 buster, this problem has been fixed in version 2018.76-5+deb10u2.

See Also

https://security-tracker.debian.org/tracker/source-package/dropbear

https://www.debian.org/lts/security/2022/dla-3187

https://security-tracker.debian.org/tracker/CVE-2021-36369

https://packages.debian.org/source/buster/dropbear

Plugin Details

Severity: High

ID: 167353

File Name: debian_DLA-3187.nasl

Version: 1.3

Type: local

Agent: unix

Published: 11/14/2022

Updated: 11/24/2022

Supported Sensors: Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

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

CVSS Score Source: CVE-2021-36369

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

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

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:debian:debian_linux:dropbear, p-cpe:/a:debian:debian_linux:dropbear-initramfs, cpe:/o:debian:debian_linux:10.0, p-cpe:/a:debian:debian_linux:dropbear-bin, p-cpe:/a:debian:debian_linux:dropbear-run

Required KB Items: Host/local_checks_enabled, Host/Debian/release, Host/Debian/dpkg-l

Exploit Ease: No known exploits are available

Patch Publication Date: 11/14/2022

Vulnerability Publication Date: 10/12/2022

Reference Information

CVE: CVE-2021-36369