libssh 0.6.x / 0.7.x < 0.7.6 / 0.8.x < 0.8.4 Authentication Bypass (Remote Version Check)

critical Nessus Plugin ID 118155
New! Plugin Severity Now Using CVSS v3

The calculated severity for Plugins has been updated to use CVSS v3 by default. Plugins that do not have a CVSS v3 score will fall back to CVSS v2 for calculating severity. Severity display preferences can be toggled in the settings dropdown.


The remote server is vulnerable to an authentication bypass.


According to its banner version, the remote libssh based server is vulnerable to an authentication bypass. An attacker can bypass authentication by presenting a SSH2_MSG_USERAUTH_SUCCESS message in place of the SSH2_MSG_USERAUTH_REQUEST method that normally would initiate authentication.

Note that Nessus did not actually test for the flaw but instead has relied on the version in the libssh banner so this may be a false positive.


Upgrade to libssh 0.7.6 / 0.8.4 or later.

See Also

Plugin Details

Severity: Critical

ID: 118155

File Name: libssh_0_8_4.nasl

Version: 1.16

Type: remote

Family: Misc.

Published: 10/17/2018

Updated: 5/15/2020

Dependencies: find_service1.nasl

Configuration: Enable paranoid mode

Risk Information

CVSS Score Source: CVE-2018-10933


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

Required KB Items: Settings/ParanoidReport

Exploit Available: true

Exploit Ease: Exploits are available

Vulnerability Publication Date: 10/16/2018

Reference Information

CVE: CVE-2018-10933

IAVA: 2018-A-0347-S