Vulnerability · Published Nov 5, 2025 · Assigned by cisco
CVE-2025-20343Cisco Identity Services Engine Radius Suppression Denial of Service Vulnerability
High 8.6
In plain English
A high-severity security flaw in Cisco Identity Services Engine Software from Cisco. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 54% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code.
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Cisco | Cisco Identity Services Engine Software | 3.4.03.4 Patch 13.4 Patch 23.4 Patch 3 |
Weakness: CWE-697 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H