Ubuntu 20.04 LTS / 22.04 LTS / 23.04 / 23.10 : libssh vulnerability (USN-6561-1)

high Nessus Plugin ID 187106

Synopsis

The remote Ubuntu host is missing a security update.

Description

The remote Ubuntu 20.04 LTS / 22.04 LTS / 23.04 / 23.10 host has packages installed that are affected by a vulnerability as referenced in the USN-6561-1 advisory.

Fabian Bumer, Marcus Brinkmann, Jrg Schwenk discovered that the SSH protocol was vulnerable to a prefix truncation attack. If a remote attacker was able to intercept SSH communications, extension negotiation messages could be truncated, possibly leading to certain algorithms and features being downgraded. This issue is known as the Terrapin attack. This update adds protocol extensions to mitigate this issue.

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

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

Solution

Update the affected packages.

See Also

https://ubuntu.com/security/notices/USN-6561-1

Plugin Details

Severity: High

ID: 187106

File Name: ubuntu_USN-6561-1.nasl

Version: 1.6

Type: local

Agent: unix

Published: 12/19/2023

Updated: 9/18/2024

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.1

CVSS v2

Risk Factor: Medium

Base Score: 5.4

Temporal Score: 4.2

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

CVSS Score Source: CVE-2023-48795

CVSS v3

Risk Factor: Medium

Base Score: 5.9

Temporal Score: 5.3

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

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

CVSS v4

Risk Factor: High

Base Score: 8.9

Threat Score: 8.9

Threat Vector: CVSS:4.0/E:P

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:23.10, cpe:/o:canonical:ubuntu_linux:20.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:libssh-gcrypt-dev, cpe:/o:canonical:ubuntu_linux:23.04, cpe:/o:canonical:ubuntu_linux:22.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:libssh-gcrypt-4, p-cpe:/a:canonical:ubuntu_linux:libssh-4, p-cpe:/a:canonical:ubuntu_linux:libssh-dev

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 12/19/2023

Vulnerability Publication Date: 12/18/2023

Reference Information

CVE: CVE-2023-48795

IAVA: 2023-A-0703

USN: 6561-1