Cisco Nexus 9000 Series Fabric Switches ACI Mode Link Layer Discovery Protocol Port Denial of Service (CVE-2021-1231)

medium Tenable OT Security Plugin ID 501409

Synopsis

The remote OT asset is affected by a vulnerability.

Description

A vulnerability in the Link Layer Discovery Protocol (LLDP) for Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) mode could allow an unauthenticated, adjacent attacker to disable switching on a small form-factor pluggable (SFP) interface.
This vulnerability is due to incomplete validation of the source of a received LLDP packet. An attacker could exploit this vulnerability by sending a crafted LLDP packet on an SFP interface to an affected device. A successful exploit could allow the attacker to disable switching on the SFP interface, which could disrupt network traffic.

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Solution

Refer to the vendor advisory.

Plugin Details

Severity: Medium

ID: 501409

Version: 1.2

Type: remote

Family: Tenable.ot

Published: 7/25/2023

Updated: 10/16/2025

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Low

Score: 1.6

CVSS v2

Risk Factor: Low

Base Score: 2.9

Temporal Score: 2.1

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

CVSS Score Source: CVE-2021-1231

CVSS v3

Risk Factor: Medium

Base Score: 4.7

Temporal Score: 4.1

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

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

Vulnerability Information

CPE: cpe:/o:cisco:nexus_9000_series_switches

Required KB Items: Tenable.ot/Cisco

Exploit Ease: No known exploits are available

Patch Publication Date: 2/24/2021

Vulnerability Publication Date: 2/24/2021

Reference Information

CVE: CVE-2021-1231

CWE: 346

Detections

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