NVD / CVE Program· CNA cisco

CVE-2021-1230: Cisco Nexus 9000 Series Fabric Switches ACI Mode BGP Route Installation Denial of Service Vulnerability

Noroxi assessment

Priority: Monitor (action score 30/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 1.5% (FIRST EPSS); higher than 74.8% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
According to the record, no fixed version is available yet.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 7.5 · v3.1—No exploit No fix recorded

BDU:2021-01084

Published: Feb 24, 2021
Updated: Jun 16, 2026
EPSS: 1.5% · 74th percentile
CWE: CWE-233

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 30 / 40 · 7.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 1.5%

CISA SSVC decision

Exploitation: none
Automatable: yes
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: 7.5
CNA · cisco: 8.6; 1.1 point gap

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
cisco	nx-os	cpe:2.3:o:cisco:nx-os
cisco	nexus 9000v	cpe:2.3:h:cisco:nexus_9000v
cisco	nexus 92160yc-x	cpe:2.3:h:cisco:nexus_92160yc-x
cisco	nexus 92300yc	cpe:2.3:h:cisco:nexus_92300yc
cisco	nexus 92304qc	cpe:2.3:h:cisco:nexus_92304qc
cisco	nexus 92348gc-x	cpe:2.3:h:cisco:nexus_92348gc-x
cisco	nexus 9236c	cpe:2.3:h:cisco:nexus_9236c
cisco	nexus 9272q	cpe:2.3:h:cisco:nexus_9272q
cisco	nexus 93108tc-ex	cpe:2.3:h:cisco:nexus_93108tc-ex
cisco	nexus 93108tc-ex-24	cpe:2.3:h:cisco:nexus_93108tc-ex-24
cisco	nexus 93108tc-fx	cpe:2.3:h:cisco:nexus_93108tc-fx
cisco	nexus 93108tc-fx-24	cpe:2.3:h:cisco:nexus_93108tc-fx-24

and 29 more

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

cisco nx-os12.0(1m)
cisco nx-os12.0(1n)
cisco nx-os12.0(1o)
cisco nx-os12.0(1p)
cisco nx-os12.0(1q)
cisco nx-os12.0(1r)
cisco nx-os12.0(2f)
cisco nx-os12.0(2g)
cisco nx-os12.0(2h)
cisco nx-os12.0(2l)
cisco nx-os12.0(2m)
cisco nx-os12.0(2n)
cisco nx-os12.0(2o)
cisco nx-os12.1(1h)
cisco nx-os12.1(1i)
cisco nx-os12.1(2e)
cisco nx-os12.1(2g)
cisco nx-os12.1(2k)
cisco nx-os12.1(3g)
cisco nx-os12.1(3h)

Versions reported by the vendor

Affected version ranges reported by the assigning authority (cisco). Independent of NVD's CPE analysis and usually ahead of it.

Cisco Cisco NX-OS System Software in ACI Mode
- n/aaffected

Same product

cisco: all records

Other highest-scoring records for the same primary product.

CVE-2024-20399Cisco NX-OS Software CLI Command Injection VulnerabilityKEV
57Plan
CVE-2018-0301A vulnerability in the NX-API feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to craft a packet to the manag
44Plan
CVE-2016-1453Buffer overflow in the Overlay Transport Virtualization (OTV) GRE feature in Cisco NX-OS 5.0 through 7.3 on Nexus 7000 and 7700 devices allo
41Plan

Published before and after this one in the same product

← EarlierCVE-2021-1228Feb 24, 2021 · Cisco Nexus 9000 Series Fabric Switches ACI Mode Fabric Infrastructure VLAN Unauthorized Access Vulnerability
26Monitor
← EarlierCVE-2021-1229Feb 24, 2021 · Cisco NX-OS Software ICMP Version 6 Memory Leak Denial of Service Vulnerability
21Monitor
Later →CVE-2021-1231Feb 24, 2021 · Cisco Nexus 9000 Series Fabric Switches ACI Mode Link Layer Discovery Protocol Port Denial of Service Vulnerability
18Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).