{"cve":"CVE-2023-20243","nvd":{"published":"2023-09-06T18:15:08.133","modified":"2026-06-17T05:30:00.780","status":"Modified","description":"A vulnerability in the RADIUS message processing feature of Cisco Identity Services Engine (ISE) could allow an unauthenticated, remote attacker to cause the affected system to stop processing RADIUS packets.\r\n\r This vulnerability is due to improper handling of certain RADIUS accounting requests. An attacker could exploit this vulnerability by sending a crafted authentication request to a network access device (NAD) that uses Cisco ISE for authentication, authorization, and accounting (AAA). This would eventually result in the NAD sending a RADIUS accounting request packet to Cisco ISE. An attacker could also exploit this vulnerability by sending a crafted RADIUS accounting request packet to Cisco ISE directly if the RADIUS shared secret is known. A successful exploit could allow the attacker to cause the RADIUS process to unexpectedly restart, resulting in authentication or authorization timeouts and denying legitimate users access to the network or service. Clients already authenticated to the network would not be affected.\r\n\r Note: To recover the ability to process RADIUS packets, a manual restart of the affected Policy Service Node (PSN) may be required. For more information, see the Details [\"#details\"] section of this advisory.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","score":8.6},"cwes":["CWE-755","CWE-399"],"references":["https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ise-radius-dos-W7cNn7gt","https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ise-radius-dos-W7cNn7gt"],"products":["cisco:identity_services_engine"],"source":"nvd","synced_at":"2026-10-19T21:39:24.235896374+00:00"},"epss":{"cve":"CVE-2023-20243","score":0.00916,"percentile":0.60199,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}