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CVE-2021-1230

Cisco Nexus 9000 Series Fabric Switches ACI Mode BGP Route Installation Denial of Service Vulnerability

HIGH
7.5
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
HIGH7.5
Exploit prediction
EPSS 2%
SSVC
No known exploit

Description

A vulnerability with the Border Gateway Protocol (BGP) for Cisco Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) mode could allow an unauthenticated, remote attacker to cause a routing process to crash, which could lead to a denial of service (DoS) condition. This vulnerability is due to an issue with the installation of routes upon receipt of a BGP update. An attacker could exploit this vulnerability by sending a crafted BGP update to an affected device. A successful exploit could allow the attacker to cause the routing process to crash, which could cause the device to reload. This vulnerability applies to both Internal BGP (IBGP) and External BGP (EBGP). Note: The Cisco implementation of BGP accepts incoming BGP traffic from explicitly configured peers only. To exploit this vulnerability, an attacker would need to send a specific BGP update message over an established TCP connection that appears to come from a trusted BGP peer.

Affected

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

Nx OS· Cisconpm
95%
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)
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
Nexus 92348Gc-X· Ciscodevice
80%
All versions
Nexus 9236C· Ciscodevice
80%
All versions
Nexus 9272Q· Ciscodevice
80%
All versions
Nexus 93108Tc-Ex· Ciscodevice
80%
All versions
Nexus 93108Tc-Ex-24· Ciscodevice
80%
All versions

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

References (1)

Vendor Advisoryx_refsource_CISCO
Source: [email protected]
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-n9kaci-bgp-De9dPKSK

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGH[email protected]
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-233NVD-CWE-Other

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