CVE-2025-20343

Published Nov 5, 2025

Last updated 16 days ago

Overview

AI description

Automated description summarized from trusted sources.

CVE-2025-20343 is a vulnerability in the RADIUS setting "Reject RADIUS requests from clients with repeated failures" on Cisco Identity Services Engine (ISE). This vulnerability could allow an unauthenticated, remote attacker to cause the Cisco ISE to restart unexpectedly. The 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.

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.
Source: psirt@cisco.com
NVD status: Analyzed
Products: identity_services_engine

Risk scores

CVSS 3.1

Type: Primary
Base score: 7.5
Impact score: 3.6
Exploitability score: 3.9
Vector string: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Severity: HIGH

Weaknesses

psirt@cisco.com: CWE-697

Hype score: Not currently trending

Configurations

[
  {
    "nodes": [
      {
        "negate": false,
        "cpeMatch": [
          {
            "criteria": "cpe:2.3:a:cisco:identity_services_engine:3.4.0:-:*:*:*:*:*:*",
            "vulnerable": true,
            "matchCriteriaId": "D23905E0-E525-49B1-8E5F-4EB42D186768"
          },
          {
            "criteria": "cpe:2.3:a:cisco:identity_services_engine:3.4.0:patch1:*:*:*:*:*:*",
            "vulnerable": true,
            "matchCriteriaId": "74509498-38EF-4345-9583-CEF5C26CA1D8"
          },
          {
            "criteria": "cpe:2.3:a:cisco:identity_services_engine:3.4.0:patch2:*:*:*:*:*:*",
            "vulnerable": true,
            "matchCriteriaId": "CD05FF93-7B8C-4283-9DB7-E03FE98FAADF"
          },
          {
            "criteria": "cpe:2.3:a:cisco:identity_services_engine:3.4.0:patch3:*:*:*:*:*:*",
            "vulnerable": true,
            "matchCriteriaId": "0F9B6A8E-E773-44A3-9266-878F0C58EB41"
          }
        ],
        "operator": "OR"
      }
    ]
  }
]

References

Sources include official advisories and independent security research.