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Cisco Nexus 9000 Series Fabric Switches ACI Mode Border Leaf Endpoint Learning (cisco-sa-20190828-nexus-aci-dos)

high Nessus Plugin ID 132855

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Synopsis

The remote device is missing a vendor-supplied security patch

Description

According to its self-reported version, Cisco NX-OS System Software in Application Centric Infrastructure (ACI) mode is affected by a vulnerability within the Endpoint Learning feature of Cisco 9000 Series Switches due to improper endpoint learning when packets are received on a specific port from outside the ACI fabric and destined to an endpoint located on a border leaf when 'Disable Remote Endpoint Learning' has been enabled. An unauthenticated, remote attacker can exploit this to create a Remote (XR) entry for the impacted endpoint that will become stale if the endpoint migrates to a different port or leaf switch. This results in traffic not reaching the impacted endpoint until the Remote entry can be relearned by another mechanism, causing a denial of service (DoS) condition.

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 CSCvi11291

See Also

http://www.nessus.org/u?9a5ce967

https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvi11291

Plugin Details

Severity: High

ID: 132855

File Name: cisco-sa-20190828-nexus-aci-dos.nasl

Version: 1.8

Type: combined

Family: CISCO

Published: 1/14/2020

Updated: 3/29/2021

Configuration: Enable paranoid mode

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3.6

CVSS v2

Risk Factor: Medium

Base Score: 4.3

Temporal Score: 3.2

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

CVSS Score Source: CVE-2019-1977

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

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

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

Vulnerability Information

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

Required KB Items: Settings/ParanoidReport, 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: 8/28/2019

Vulnerability Publication Date: 8/28/2019

Reference Information

CVE: CVE-2019-1977

CISCO-SA: cisco-sa-20190828-nexus-aci-dos

IAVA: 2019-A-0317

CISCO-BUG-ID: CSCvi11291