Debian DLA-1548-1 : libssh security update

critical Nessus Plugin ID 118214
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The remote Debian host is missing a security update.


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.

For Debian 8 'Jessie', this problem has been fixed in version 0.6.3-4+deb8u3.

We recommend that you upgrade your libssh packages.

NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.


Upgrade the affected packages.

See Also

Plugin Details

Severity: Critical

ID: 118214

File Name: debian_DLA-1548.nasl

Version: 1.6

Type: local

Agent: unix

Published: 10/19/2018

Updated: 1/11/2021

Dependencies: ssh_get_info.nasl

Risk Information


Risk Factor: High

Score: 7.7


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


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-4, p-cpe:/a:debian:debian_linux:libssh-dbg, p-cpe:/a:debian:debian_linux:libssh-dev, p-cpe:/a:debian:debian_linux:libssh-doc, p-cpe:/a:debian:debian_linux:libssh-gcrypt-4, p-cpe:/a:debian:debian_linux:libssh-gcrypt-dev, cpe:/o:debian:debian_linux:8.0

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: 10/18/2018

Reference Information

CVE: CVE-2018-10933

IAVA: 2018-A-0347-S