OpenSSH < 9.9p2 MitM

medium Nessus Plugin ID 216476

Synopsis

The SSH server running on the remote host is affected by a man in the middle vulnerability.

Description

The version of OpenSSH installed on the remote host is prior to 9.9p2. It is, therefore, affected by a man in the middle (MITM) vulnerability. ssh(1) in OpenSSH versions 6.8p1 to 9.9p1 (inclusive) contained a logic error that allowed an on-path attacker (a.k.a MITM) to impersonate any server when the VerifyHostKeyDNS option is enabled. This option is off by default.

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

Solution

Upgrade to OpenSSH version 9.9p2 or later.

See Also

https://www.openssh.com/txt/release-9.9p2

Plugin Details

Severity: Medium

ID: 216476

File Name: openssh_9_9_p2.nasl

Version: 1.2

Type: remote

Family: Misc.

Published: 2/19/2025

Updated: 2/20/2025

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.6

CVSS v2

Risk Factor: Medium

Base Score: 5.8

Temporal Score: 4.5

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

CVSS Score Source: CVE-2025-26465

CVSS v3

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 6.1

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

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

Vulnerability Information

CPE: cpe:/a:openbsd:openssh

Required KB Items: installed_sw/OpenSSH

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 2/18/2025

Vulnerability Publication Date: 2/18/2025

Reference Information

CVE: CVE-2025-26465