CVE-2021-1231

Cisco Nexus 9000 Series Fabric Switches ACI Mode Link Layer Discovery Protocol Port Denial of Service Vulnerability

MEDIUM

4.7

CVSS Score

Published: February 24, 2021 at 07:30 PM UTC

Updated: June 17, 2026 at 03:31 AM UTC

41 products affected across 1 vendorNx OSNexus 9508Nexus 93120Tx

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Severity

MEDIUM4.7

Exploit prediction

EPSS 0.3%

SSVC

No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Nx OS · Cisconpm

95%

11.0(1b)11.0(1c)11.0(1d)11.0(1e)11.0(2j)11.0(2m)11.0(3f)11.0(3i)11.0(3k)11.0(3n)11.0(3o)11.0(4g)11.0(4h)11.0(4o)11.0(4q)11.1(1j)11.1(1o)11.1(1r)11.1(1s)11.1(2h)11.1(2i)11.1(3f)11.1(4e)11.1(4f)11.1(4g)11.1(4i)11.1(4l)11.1(4m)11.2(1i)11.2(1k)11.2(1m)11.2(2g)11.2(2h)11.2(2i)11.2(2j)11.2(3c)11.2(3e)11.2(3h)11.2(3m)11.3(1g)11.3(1h)11.3(1i)11.3(1j)11.3(2f)11.3(2h)11.3(2i)11.3(2j)11.3(2k)12.0(1m)12.0(1n)12.0(1o)12.0(1p)12.0(1q)12.0(1r)12.0(2f)12.0(2g)12.0(2h)12.0(2l)12.0(2m)12.0(2n)12.0(2o)12.1(1h)12.1(1i)12.1(2e)12.1(2g)12.1(2k)12.1(3g)12.1(3h)12.1(3j)12.1(4a)12.2(1k)12.2(1n)12.2(1o)12.2(2e)12.2(2f)12.2(2i)12.2(2j)12.2(2k)12.2(2q)12.2(3j)12.2(3p)12.2(3r)12.2(3s)12.2(3t)12.2(4f)12.2(4p)12.2(4q)12.2(4r)12.3(1e)12.3(1f)12.3(1i)12.3(1l)12.3(1o)12.3(1p)13.0(1k)13.0(2h)13.0(2k)13.0(2n)13.1(1i)13.1(2m)13.1(2o)13.1(2p)13.1(2q)13.1(2s)13.1(2t)13.1(2u)13.1(2v)13.2(1l)13.2(1m)13.2(2l)13.2(2o)13.2(3i)13.2(3j)13.2(3n)13.2(3o)13.2(3r)13.2(3s)13.2(41d)13.2(4d)13.2(4e)13.2(5d)13.2(5e)13.2(5f)13.2(6i)13.2(7f)13.2(7k)13.2(8d)13.2(9b)13.2(9f)13.2(9h)14.0(1h)14.0(2c)14.0(3c)14.0(3d)14.1(1i)14.1(1j)14.1(1k)14.1(1l)14.1(2g)14.1(2m)14.1(2o)14.1(2s)14.1(2u)14.1(2w)14.1(2x)14.2(1i)14.2(1j)14.2(1l)14.2(2e)14.2(2f)14.2(2g)14.2(3j)14.2(3l)14.2(3n)14.2(3q)14.2(4i)14.2(4k)14.2(4o)14.2(4p)14.2(5k)15.0(1k)15.0(1l)15.0(2e)15.0(2h)

cisco-nexus-9000v (environment) · cisco-nexus-92160yc-x (environment) · cisco-nexus-92300yc (environment) · cisco-nexus-92304qc (environment) · cisco-nexus-92348gc-x (environment) · cisco-nexus-9236c (environment) · cisco-nexus-9272q (environment) · cisco-nexus-93108tc-ex (environment) · cisco-nexus-93108tc-ex-24 (environment) · cisco-nexus-93108tc-fx (environment) · cisco-nexus-93108tc-fx-24 (environment) · cisco-nexus-93120tx (environment) · cisco-nexus-93128tx (environment) · cisco-nexus-9316d-gx (environment) · cisco-nexus-93180lc-ex (environment) · cisco-nexus-93180yc-ex (environment) · cisco-nexus-93180yc-ex-24 (environment) · cisco-nexus-93180yc-fx (environment) · cisco-nexus-93180yc-fx-24 (environment) · cisco-nexus-93180yc-fx3 (environment) · cisco-nexus-93180yc-fx3s (environment) · cisco-nexus-93216tc-fx2 (environment) · cisco-nexus-93240yc-fx2 (environment) · cisco-nexus-9332c (environment) · cisco-nexus-9332pq (environment) · cisco-nexus-93360yc-fx2 (environment) · cisco-nexus-9336c-fx2 (environment) · cisco-nexus-9336c-fx2-e (environment) · cisco-nexus-9336pq-aci-spine (environment) · cisco-nexus-9348gc-fxp (environment) · cisco-nexus-93600cd-gx (environment) · cisco-nexus-9364c (environment) · cisco-nexus-9364c-gx (environment) · cisco-nexus-9372px (environment) · cisco-nexus-9372px-e (environment) · cisco-nexus-9372tx (environment) · cisco-nexus-9372tx-e (environment) · cisco-nexus-9396px (environment) · cisco-nexus-9396tx (environment) · cisco-nexus-9508 (environment)

Nexus 9000V · Ciscodevice

80%

All versions

Nexus 92160Yc-X · Ciscodevice

80%

All versions

Nexus 92300Yc · Ciscodevice

80%

All versions

Nexus 92304Qc · Ciscodevice

80%

All versions