CVE-2023-20213

What it is

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.

At a glance

Exploitability

Can be exploited from the same network segment without logging in. Limited direct impact.

Exploit odds

0.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2023-11-01 17:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 05:29 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.3% in the next 30 days (EPSS).
• Severity: 4.3 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2023-11-01 17:15 UTC

Last modified

2026-06-17 05:29 UTC

Exploit probability

0.3% · EPSS, next 30 days

Weakness

CWE-787 · Out-of-bounds write

Record status

Modified

Affected

• Cisco Identity Services Engine 2.7.0
• Cisco Identity Services Engine 3.0.0
• Cisco Identity Services Engine 3.1
• Cisco Identity Services Engine 3.2

Attack profile CVSS 3.1 · 4.3

Attack vector

Adjacent network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

Low

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2023-20213.md and follow it. Check whether this project is affected by CVE-2023-20213. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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