CVE-2021-1229

Cisco NX-OS Software ICMP Version 6 Memory Leak Denial of Service Vulnerability

MEDIUM

5.3

CVSS Score

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

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

86 products affected across 1 vendorNx OSNexus 9508Nexus 93120Tx

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Severity

MEDIUM5.3

Exploit prediction

EPSS 1%

SSVC

No known exploit

Description

A vulnerability in ICMP Version 6 (ICMPv6) processing in Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a slow system memory leak, which over time could lead to a denial of service (DoS) condition. This vulnerability is due to improper error handling when an IPv6-configured interface receives a specific type of ICMPv6 packet. An attacker could exploit this vulnerability by sending a sustained rate of crafted ICMPv6 packets to a local IPv6 address on a targeted device. A successful exploit could allow the attacker to cause a system memory leak in the ICMPv6 process on the device. As a result, the ICMPv6 process could run out of system memory and stop processing traffic. The device could then drop all ICMPv6 packets, causing traffic instability on the device. Restoring device functionality would require a device reboot.

Affected

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

Nx OS · Cisconpm

95%

15.1(2.31)5.2(1)sv5(1.3a)8.4(3.53)

cisco-mds-9148s (environment) · cisco-mds-9250i (environment) · cisco-mds-9706 (environment) · cisco-mds-9710 (environment) · cisco-nexus-1000-virtual-edge-for-vmware-vsphere (environment) · cisco-nexus-1000v-switch-for-microsoft-hyper-v (environment) · cisco-nexus-1000v-switch-for-vmware-vsphere (environment) · cisco-nexus-3048 (environment) · cisco-nexus-31108pv-v (environment) · cisco-nexus-31108tc-v (environment) · cisco-nexus-31128pq (environment) · cisco-nexus-3132c-z (environment) · cisco-nexus-3132q-v (environment) · cisco-nexus-3132q-x (environment) · cisco-nexus-3132q-xl (environment) · cisco-nexus-3164q (environment) · cisco-nexus-3172pq (environment) · cisco-nexus-3172pq-xl (environment) · cisco-nexus-3232c (environment) · cisco-nexus-3264c-e (environment) · cisco-nexus-3264q (environment) · cisco-nexus-3408-s (environment) · cisco-nexus-34180yc (environment) · cisco-nexus-3432d-s (environment) · cisco-nexus-3464c (environment) · cisco-nexus-3524-x (environment) · cisco-nexus-3524-xl (environment) · cisco-nexus-3548-x (environment) · cisco-nexus-3548-xl (environment) · cisco-nexus-36180yc-r (environment) · cisco-nexus-3636c-r (environment) · cisco-nexus-5548p (environment) · cisco-nexus-5548up (environment) · cisco-nexus-5596t (environment) · cisco-nexus-5596up (environment) · cisco-nexus-56128p (environment) · cisco-nexus-5624q (environment) · cisco-nexus-5648q (environment) · cisco-nexus-5672up (environment) · cisco-nexus-5672up-16g (environment) · cisco-nexus-5696q (environment) · cisco-nexus-6001 (environment) · cisco-nexus-6004 (environment) · cisco-nexus-7000 (environment) · cisco-nexus-7700 (environment) · cisco-nexus-9000v (environment) · cisco-nexus-92160yc-x (environment) · cisco-nexus-9221c (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-9332pq (environment) · cisco-nexus-93360yc-fx2 (environment) · cisco-nexus-9336c-fx2 (environment) · cisco-nexus-9336c-fx2-e (environment) · cisco-nexus-9336pq (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)

Mds 9148S · Ciscodevice

80%

All versions

Mds 9250I · Ciscodevice

80%

All versions

Mds 9706 · Ciscodevice

80%

All versions

Mds 9710 · Ciscodevice

80%

All versions