CVE-2021-1230Network attack vector

Routing-process crash via crafted BGP update

Published Feb 24, 2021 · Updated Nov 8, 2024

Denial of service in Cisco NX-OS System Software in ACI Mode allows remote attackers to crash the BGP process with a crafted update. The route-installation path accepts a specific crafted update and fails while installing its routes, terminating the routing process and potentially reloading the switch. Exploitation requires an established TCP connection that appears to originate from an explicitly configured, trusted BGP peer.

CVSS severity8.6
High
EPSS probability1.53%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Cisco NX-OS System Software in ACI Mode allows remote attackers to crash the BGP process with a crafted update. The route-installation path accepts a specific crafted update and fails while installing its routes, terminating the routing process and potentially reloading the switch. Exploitation requires an established TCP connection that appears to originate from an explicitly configured, trusted BGP peer.

The record

CVE
CVE-2021-1230
Published
Feb 24, 2021
Updated
Nov 8, 2024
Vendor
ClamAV
Product
Cisco NX-OS System Software in ACI Mode
Classifications
CWE-233, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 24, 2021CVE publishedPublication date reported by the CVE source.
  2. Nov 8, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=n/a

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco NX-OS System Software in ACI Modeversion=n/a

Published CVSS scores

8.6CiscoCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:X/RL:X/RC:X

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-233Improper Handling of Parameters
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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