medium
4.7
CWE
346 284
Advisory Published
Updated

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

First published: Wed Feb 24 2021(Updated: )

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.

Credit: ykramarz@cisco.com

Affected SoftwareAffected VersionHow to fix
Cisco NX-OS=11.0\(1b\)
Cisco NX-OS=11.0\(1c\)
Cisco NX-OS=11.0\(1d\)
Cisco NX-OS=11.0\(1e\)
Cisco NX-OS=11.0\(2j\)
Cisco NX-OS=11.0\(2m\)
Cisco NX-OS=11.0\(3f\)
Cisco NX-OS=11.0\(3i\)
Cisco NX-OS=11.0\(3k\)
Cisco NX-OS=11.0\(3n\)
Cisco NX-OS=11.0\(3o\)
Cisco NX-OS=11.0\(4g\)
Cisco NX-OS=11.0\(4h\)
Cisco NX-OS=11.0\(4o\)
Cisco NX-OS=11.0\(4q\)
Cisco NX-OS=11.1\(1j\)
Cisco NX-OS=11.1\(1o\)
Cisco NX-OS=11.1\(1r\)
Cisco NX-OS=11.1\(1s\)
Cisco NX-OS=11.1\(2h\)
Cisco NX-OS=11.1\(2i\)
Cisco NX-OS=11.1\(3f\)
Cisco NX-OS=11.1\(4e\)
Cisco NX-OS=11.1\(4f\)
Cisco NX-OS=11.1\(4g\)
Cisco NX-OS=11.1\(4i\)
Cisco NX-OS=11.1\(4l\)
Cisco NX-OS=11.1\(4m\)
Cisco NX-OS=11.2\(1i\)
Cisco NX-OS=11.2\(1k\)
Cisco NX-OS=11.2\(1m\)
Cisco NX-OS=11.2\(2g\)
Cisco NX-OS=11.2\(2h\)
Cisco NX-OS=11.2\(2i\)
Cisco NX-OS=11.2\(2j\)
Cisco NX-OS=11.2\(3c\)
Cisco NX-OS=11.2\(3e\)
Cisco NX-OS=11.2\(3h\)
Cisco NX-OS=11.2\(3m\)
Cisco NX-OS=11.3\(1g\)
Cisco NX-OS=11.3\(1h\)
Cisco NX-OS=11.3\(1i\)
Cisco NX-OS=11.3\(1j\)
Cisco NX-OS=11.3\(2f\)
Cisco NX-OS=11.3\(2h\)
Cisco NX-OS=11.3\(2i\)
Cisco NX-OS=11.3\(2j\)
Cisco NX-OS=11.3\(2k\)
Cisco NX-OS=12.0\(1m\)
Cisco NX-OS=12.0\(1n\)
Cisco NX-OS=12.0\(1o\)
Cisco NX-OS=12.0\(1p\)
Cisco NX-OS=12.0\(1q\)
Cisco NX-OS=12.0\(1r\)
Cisco NX-OS=12.0\(2f\)
Cisco NX-OS=12.0\(2g\)
Cisco NX-OS=12.0\(2h\)
Cisco NX-OS=12.0\(2l\)
Cisco NX-OS=12.0\(2m\)
Cisco NX-OS=12.0\(2n\)
Cisco NX-OS=12.0\(2o\)
Cisco NX-OS=12.1\(1h\)
Cisco NX-OS=12.1\(1i\)
Cisco NX-OS=12.1\(2e\)
Cisco NX-OS=12.1\(2g\)
Cisco NX-OS=12.1\(2k\)
Cisco NX-OS=12.1\(3g\)
Cisco NX-OS=12.1\(3h\)
Cisco NX-OS=12.1\(3j\)
Cisco NX-OS=12.1\(4a\)
Cisco NX-OS=12.2\(1k\)
Cisco NX-OS=12.2\(1n\)
Cisco NX-OS=12.2\(1o\)
Cisco NX-OS=12.2\(2e\)
Cisco NX-OS=12.2\(2f\)
Cisco NX-OS=12.2\(2i\)
Cisco NX-OS=12.2\(2j\)
Cisco NX-OS=12.2\(2k\)
Cisco NX-OS=12.2\(2q\)
Cisco NX-OS=12.2\(3j\)
Cisco NX-OS=12.2\(3p\)
Cisco NX-OS=12.2\(3r\)
Cisco NX-OS=12.2\(3s\)
Cisco NX-OS=12.2\(3t\)
Cisco NX-OS=12.2\(4f\)
Cisco NX-OS=12.2\(4p\)
Cisco NX-OS=12.2\(4q\)
Cisco NX-OS=12.2\(4r\)
Cisco NX-OS=12.3\(1e\)
Cisco NX-OS=12.3\(1f\)
Cisco NX-OS=12.3\(1i\)
Cisco NX-OS=12.3\(1l\)
Cisco NX-OS=12.3\(1o\)
Cisco NX-OS=12.3\(1p\)
Cisco NX-OS=13.0\(1k\)
Cisco NX-OS=13.0\(2h\)
Cisco NX-OS=13.0\(2k\)
Cisco NX-OS=13.0\(2n\)
Cisco NX-OS=13.1\(1i\)
Cisco NX-OS=13.1\(2m\)
Cisco NX-OS=13.1\(2o\)
Cisco NX-OS=13.1\(2p\)
Cisco NX-OS=13.1\(2q\)
Cisco NX-OS=13.1\(2s\)
Cisco NX-OS=13.1\(2t\)
Cisco NX-OS=13.1\(2u\)
Cisco NX-OS=13.1\(2v\)
Cisco NX-OS=13.2\(1l\)
Cisco NX-OS=13.2\(1m\)
Cisco NX-OS=13.2\(2l\)
Cisco NX-OS=13.2\(2o\)
Cisco NX-OS=13.2\(3i\)
Cisco NX-OS=13.2\(3j\)
Cisco NX-OS=13.2\(3n\)
Cisco NX-OS=13.2\(3o\)
Cisco NX-OS=13.2\(3r\)
Cisco NX-OS=13.2\(3s\)
Cisco NX-OS=13.2\(4d\)
Cisco NX-OS=13.2\(4e\)
Cisco NX-OS=13.2\(5d\)
Cisco NX-OS=13.2\(5e\)
Cisco NX-OS=13.2\(5f\)
Cisco NX-OS=13.2\(6i\)
Cisco NX-OS=13.2\(7f\)
Cisco NX-OS=13.2\(7k\)
Cisco NX-OS=13.2\(8d\)
Cisco NX-OS=13.2\(9b\)
Cisco NX-OS=13.2\(9f\)
Cisco NX-OS=13.2\(9h\)
Cisco NX-OS=13.2\(41d\)
Cisco NX-OS=14.0\(1h\)
Cisco NX-OS=14.0\(2c\)
Cisco NX-OS=14.0\(3c\)
Cisco NX-OS=14.0\(3d\)
Cisco NX-OS=14.1\(1i\)
Cisco NX-OS=14.1\(1j\)
Cisco NX-OS=14.1\(1k\)
Cisco NX-OS=14.1\(1l\)
Cisco NX-OS=14.1\(2g\)
Cisco NX-OS=14.1\(2m\)
Cisco NX-OS=14.1\(2o\)
Cisco NX-OS=14.1\(2s\)
Cisco NX-OS=14.1\(2u\)
Cisco NX-OS=14.1\(2w\)
Cisco NX-OS=14.1\(2x\)
Cisco NX-OS=14.2\(1i\)
Cisco NX-OS=14.2\(1j\)
Cisco NX-OS=14.2\(1l\)
Cisco NX-OS=14.2\(2e\)
Cisco NX-OS=14.2\(2f\)
Cisco NX-OS=14.2\(2g\)
Cisco NX-OS=14.2\(3j\)
Cisco NX-OS=14.2\(3l\)
Cisco NX-OS=14.2\(3n\)
Cisco NX-OS=14.2\(3q\)
Cisco NX-OS=14.2\(4i\)
Cisco NX-OS=14.2\(4k\)
Cisco NX-OS=14.2\(4o\)
Cisco NX-OS=14.2\(4p\)
Cisco NX-OS=14.2\(5k\)
Cisco NX-OS=15.0\(1k\)
Cisco NX-OS=15.0\(1l\)
Cisco NX-OS=15.0\(2e\)
Cisco NX-OS=15.0\(2h\)
Cisco NX-OS Nexus 9000 Series
Cisco Nexus 92160YC Switch
Cisco Nexus 92300YC Firmware
Cisco Nexus 92304QC Switch
Cisco Nexus 92348GC-X Switch
Cisco Nexus 9236C Switch
Cisco Nexus 9272Q Switch
Cisco Nexus
Cisco Nexus 93108TC-EX-24 Firmware
Cisco Nexus 93108TC-FX Switch
Cisco Nexus 93108TC-FX Switch
Cisco Nexus 93120TX Firmware
Cisco Nexus 93128 Firmware
Cisco Nexus 9316D-GX Firmware
Cisco Nexus 93180LC-EX Switch
Cisco Nexus 93180YC-EX-24
Cisco Nexus 93180YC-EX-24 Firmware
Cisco Nexus 93180YC-FX Firmware
Cisco Nexus 93180YC-FX-24 Firmware
Cisco Nexus 93180YC-FX3 Firmware
Cisco Nexus 93180YC-FX3S Firmware
Cisco Nexus 93216TC-FX2 Firmware
Cisco Nexus 93240YC-FX2 Firmware
Cisco Nexus 9332C Firmware
Cisco Nexus 9332PQ Firmware
Cisco Nexus 93360YC-FX2
Cisco Nexus 9336C-FX2 Firmware
Cisco Nexus 9336C-FX2-E Firmware
Cisco Nexus N9336PQ-X
Cisco Nexus 9348GC-FXP Firmware
Cisco Nexus 93600CD-GX Firmware
Cisco Nexus 9364c-h1
Cisco Nexus 9364C-GX Firmware
Cisco Nexus 9372PX-E
Cisco Nexus 9372PX-E Firmware
Cisco Nexus 9372TX
Cisco Nexus 9372TX-E Switch
Cisco Nexus 9396PX Firmware
Cisco Nexus 9396TX Firmware
Cisco Nexus 9508

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Reference Links

Frequently Asked Questions

  • What is the severity of CVE-2021-1231?

    CVE-2021-1231 has been rated as high severity due to the potential for unauthenticated attackers to disrupt network services.

  • How do I fix CVE-2021-1231?

    To fix CVE-2021-1231, update to the latest version of Cisco NX-OS that addresses the vulnerability.

  • Who is affected by CVE-2021-1231?

    CVE-2021-1231 affects several versions of Cisco NX-OS running on Nexus 9000 Series Fabric Switches in ACI mode.

  • What kind of attacks can exploit CVE-2021-1231?

    CVE-2021-1231 can be exploited by an unauthenticated, adjacent attacker to disable switching on affected SFP interfaces.

  • When was CVE-2021-1231 disclosed?

    CVE-2021-1231 was disclosed in 2021 as part of Cisco's security advisory.

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