CVE-2025-20343: identity services — Fix

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.

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CVSS v3.1 Score

8.6

HIGH

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

Weakness Type (CWE)

CWE-697 CWE-697

Affected Products

Vendor	Product	Versions
cisco	identity_services_engine	All
cisco	identity_services_engine	All
cisco	identity_services_engine	All
cisco	identity_services_engine	All

References

Advisories & Patches

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ise-radsupress-dos-8YF3JThh

Frequently Asked Questions

What is CVE-2025-20343? +

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. It has a CVSS v3.1 base score of 8.6 (HIGH).

How severe is CVE-2025-20343? +

CVE-2025-20343 has a CVSS v3.1 score of 8.6 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-20343? +

CVE-2025-20343 affects products from cisco, specifically: identity_services_engine. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-20343? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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