Juniper ScreenOS SSH / Telnet Authentication Backdoor

critical Nessus Plugin ID 87601
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.

Synopsis

An account on the remote host uses a known password.

Description

The account 'netscreen' on the remote host has the password '<<< %s(un='%s') = %u', a known backdoor password. The affected devices are firewalls and VPN gateways. A remote attacker can exploit this vulnerability to gain administrative access and monitor network traffic, deny network access, and alter device and firewall configurations.

Solution

Upgrade to Juniper ScreenOS 6.2.0r19 / 6.3.0r21 or later.
Alternatively, apply the appropriate patch referenced in the vendor advisory.

See Also

http://www.nessus.org/u?f6cfb32d

https://kb.juniper.net/InfoCenter/index?page=content&id=JSA10713

Plugin Details

Severity: Critical

ID: 87601

File Name: screenos_ssh_auth_bypass.nasl

Version: 1.10

Type: remote

Published: 12/23/2015

Updated: 7/27/2018

Dependencies: ssh_detect.nasl, account_check.nasl, telnetserver_detect_type_nd_version.nasl

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.7

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

Temporal Vector: E:U/RL:TF/RC:C

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.6

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

Temporal Vector: E:U/RL:T/RC:C

Vulnerability Information

Excluded KB Items: global_settings/supplied_logins_only

Exploit Ease: No known exploits are available

Patch Publication Date: 12/17/2015

Vulnerability Publication Date: 12/17/2015

Reference Information

CVE: CVE-2015-7755

BID: 79626

JSA: JSA10713

CERT: 640184