Cisco NX-OS Software Bash Bypass Guest Shell (cisco-sa-20190515-nxos-bash-bypass)

medium Nessus Plugin ID 132678

Synopsis

The remote device is missing a vendor-supplied security patch

Description

According to its self-reported version, Cisco NX-OS Software is affected by following vulnerability in the Bash shell implementation due to the incorrect implementation of a CLI command that allows a Bash command to be incorrectly invoked on the Guest Shell CLI. An authenticated, local attacker can exploit this, by authenticating to the device and entering a crafted command at the Guest Shell prompt, to bypass the limited command set of the restricted Guest Shell and execute commands at the privilege level of a network-admin user outside of the Guest Shell.

Please see the included Cisco BIDs and Cisco Security Advisory for more information

Solution

Upgrade to the relevant fixed version referenced in Cisco bug ID CSCvh76090, CSCvj01472, and CSCvj01497.

See Also

http://www.nessus.org/u?d0c1d1a8

https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvh76090

https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvj01472

https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvj01497

Plugin Details

Severity: Medium

ID: 132678

File Name: cisco-sa-20190515-nxos-bash-bypass.nasl

Version: 1.4

Type: combined

Family: CISCO

Published: 1/7/2020

Updated: 1/9/2020

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 5.3

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

CVSS Score Source: CVE-2019-1730

CVSS v3

Risk Factor: Medium

Base Score: 6.7

Temporal Score: 5.8

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

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

Vulnerability Information

CPE: cpe:/o:cisco:nx-os

Required KB Items: Host/Cisco/NX-OS/Version, Host/Cisco/NX-OS/Model, Host/Cisco/NX-OS/Device

Exploit Ease: No known exploits are available

Patch Publication Date: 5/15/2019

Vulnerability Publication Date: 5/15/2019

Reference Information

CVE: CVE-2019-1730

BID: 108397

CISCO-SA: cisco-sa-20190515-nxos-bash-bypass

IAVA: 2019-A-0173

CISCO-BUG-ID: CSCvh76090, CSCvj01472, CSCvj01497