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 (DoS) condit...

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.

Metrics

CVSS 3.1

4.3/10

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS Probability

0.30%

21.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-787

Affected Software

Vendor	Product	Versions
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

References

Timeline

Published: Nov 1, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is 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 (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.

How severe is CVE-2023-20213?

CVE-2023-20213 has a CVSS score of 4.3/10 (MEDIUM severity). The EPSS model estimates a 0.30% probability of exploitation in the next 30 days.

How do I fix CVE-2023-20213?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.