OpenSSH 9.1 Double Free

medium Nessus Plugin ID 171133


The SSH server running on the remote host is affected by a double free vulnerability.


The version of OpenSSH installed on the remote host is 9.1. It is, therefore, affected by a double-free vulnerability during options.kex_algorithms handling. The double free can be triggered by an unauthenticated attacker in the default configuration; however, the vulnerability discoverer reports that 'exploiting this vulnerability will not be easy.'

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


Upgrade to OpenSSH version 9.2 or later.

See Also

Plugin Details

Severity: Medium

ID: 171133

File Name: openssh_92.nasl

Version: 1.7

Type: remote

Family: Misc.

Published: 2/8/2023

Updated: 9/5/2023

Configuration: Enable paranoid mode

Risk Information


Risk Factor: Medium

Score: 6.7


Risk Factor: Medium

Base Score: 6.1

Temporal Score: 4.8

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

CVSS Score Source: CVE-2023-25136


Risk Factor: Medium

Base Score: 6.5

Temporal Score: 5.9

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

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

Vulnerability Information

CPE: cpe:/a:openbsd:openssh

Required KB Items: Settings/ParanoidReport

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 2/2/2023

Vulnerability Publication Date: 2/2/2023

Reference Information

CVE: CVE-2023-25136

IAVA: 2023-A-0073-S