CVE-2025-20343 — HIGH (8.6)

Vulnerability Description

A vulnerability in the RADIUS setting Reject RADIUS requests from clients with repeated failures on Cisco Identity Services Engine (ISE) could allow an unauthenticated, remote attacker to cause Cisco ISE to restart unexpectedly. This vulnerability is due to a logic error when processing a RADIUS access request for a MAC address that is already a rejected endpoint. An attacker could exploit this vulnerability by sending a specific sequence of multiple crafted RADIUS access request messages to Cisco ISE. A successful exploit could allow the attacker to cause a denial of service (DoS) condition when Cisco ISE restarts.

CVSS Score

8.6

HIGH

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

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

CHANGED

Confidentiality

NONE

Integrity

NONE

Availability

HIGH

Affected Products

Vendor	Product	Versions
Cisco	Identity Services Engine	3.4.0

Related Weaknesses (CWE)

CWE-697

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/ciVendor Advisory

FAQ

What is CVE-2025-20343?

CVE-2025-20343 is a vulnerability with a CVSS score of 8.6 (HIGH). A vulnerability in the RADIUS setting Reject RADIUS requests from clients with repeated failures on Cisco Identity Services Engine (ISE) could allow an unauthenticated, remote attacker to cause Cisco ...

How severe is CVE-2025-20343?

CVE-2025-20343 has been rated HIGH with a CVSS base score of 8.6/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2025-20343?

Check the references section above for vendor advisories and patch information. Affected products include: Cisco Identity Services Engine.