CVE-2025-20343 - CVE House
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Status published High CVE-2025-20343

Cisco Identity Services Engine Radius Suppression Denial of Service Vulnerability

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.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

Affected Vendor

Affected Software

Cisco Identity Services Engine Software
Vulnerable Versions:
3.4.0, 3.4 Patch 1, 3.4 Patch 2, 3.4 Patch 3

Timeline

Official Publish: November 5th, 2025
Last Modified: November 5th, 2025
Added to House: July 22nd, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Weaknesses (CWE)

MITRE ATT&CK TTPs

No associated TTPs found for this vulnerability.