Debian DSA-4322-1 : libssh - security update

critical Nessus Plugin ID 118180
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Synopsis

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

Description

Peter Winter-Smith of NCC Group discovered that libssh, a tiny C SSH library, contains an authentication bypass vulnerability in the server code. An attacker can take advantage of this flaw to successfully authenticate without any credentials by presenting the server an SSH2_MSG_USERAUTH_SUCCESS message in place of the SSH2_MSG_USERAUTH_REQUEST message which the server would expect to initiate authentication.

Solution

Upgrade the libssh packages.

For the stable distribution (stretch), this problem has been fixed in version 0.7.3-2+deb9u1.

See Also

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=911149

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

https://packages.debian.org/source/stretch/libssh

https://www.debian.org/security/2018/dsa-4322

Plugin Details

Severity: Critical

ID: 118180

File Name: debian_DSA-4322.nasl

Version: 1.7

Type: local

Agent: unix

Published: 10/18/2018

Updated: 5/15/2020

Dependencies: ssh_get_info.nasl

Risk Information

VPR

Risk Factor: High

Score: 7.7

CVSS v2

Risk Factor: Medium

Base Score: 6.4

Temporal Score: 5

Vector: AV:N/AC:L/Au:N/C:P/I:P/A:N

Temporal Vector: E:POC/RL:OF/RC:C

CVSS v3

Risk Factor: Critical

Base Score: 9.1

Temporal Score: 8.2

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

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

Vulnerability Information

CPE: p-cpe:/a:debian:debian_linux:libssh, cpe:/o:debian:debian_linux:9.0

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 10/17/2018

Reference Information

CVE: CVE-2018-10933

DSA: 4322

IAVA: 2018-A-0347-S