Weak Debian OpenSSH Keys in ~/.ssh/authorized_keys

critical Nessus Plugin ID 32320

Synopsis

The remote SSH host is set up to accept authentication with weak Debian SSH keys.

Description

The remote host has one or more ~/.ssh/authorized_keys files containing weak SSH public keys generated on a Debian or Ubuntu system.

The problem is due to a Debian packager removing nearly all sources of entropy in the remote version of OpenSSL.

This problem does not only affect Debian since any user uploading a weak SSH key into the ~/.ssh/authorized_keys file will compromise the security of the remote system.

An attacker could try a brute-force attack against the remote host and logon using these weak keys.

Solution

Remove all the offending entries from ~/.ssh/authorized_keys.

Plugin Details

Severity: Critical

ID: 32320

File Name: ssh_debian_find_weak_keys.nasl

Version: 1.33

Type: local

Agent: unix

Published: 5/15/2008

Updated: 6/29/2022

Configuration: Enable thorough checks

Supported Sensors: Nessus Agent

Risk Information

VPR

Risk Factor: High

Score: 7.4

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 8.3

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

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

CVSS Score Source: CVE-2008-0166

CVSS v3

Risk Factor: Critical

Base Score: 9.8

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

Vulnerability Information

Required KB Items: Host/local_checks_enabled, Host/uname

Exploit Available: true

Exploit Ease: Exploits are available

Vulnerability Publication Date: 5/14/2008

Exploitable With

Core Impact

Reference Information

CVE: CVE-2008-0166

BID: 29179

CERT: 925211

EDB-ID: 5720

CWE: 310