CVE-2020-3174

Traffic disruption via invalid gratuitous ARP learning

Published Feb 26, 2020 · Updated Nov 15, 2024

Improper ARP validation in Cisco NX-OS Software allows attackers to disrupt traffic by sending malicious GARP packets. The anycast gateway feature learns nonlocal subnet addresses from received gratuitous ARP requests without adequate validation, corrupting the device's ARP table. Exploitation requires local-subnet access and an enabled anycast gateway feature; incorrect entries can disrupt traffic but do not expose data.

CVSS severity4.7
Medium
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper ARP validation in Cisco NX-OS Software allows attackers to disrupt traffic by sending malicious GARP packets. The anycast gateway feature learns nonlocal subnet addresses from received gratuitous ARP requests without adequate validation, corrupting the device's ARP table. Exploitation requires local-subnet access and an enabled anycast gateway feature; incorrect entries can disrupt traffic but do not expose data.

The record

CVE
CVE-2020-3174
Published
Feb 26, 2020
Updated
Nov 15, 2024
Vendor
ClamAV
Product
Cisco NX-OS Software
Classifications
CWE-345
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 26, 2020CVE publishedPublication date reported by the CVE source.
  2. Nov 15, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=unspecified <n/a

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco NX-OS Softwareversion=unspecified <n/a

Published CVSS scores

4.7CiscoCVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-345Insufficient Verification of Data Authenticity

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo