{"cve":"CVE-2020-3221","nvd":{"published":"2020-06-03T18:15:20.103","modified":"2026-06-17T03:17:41.467","status":"Modified","description":"A vulnerability in the Flexible NetFlow Version 9 packet processor of Cisco IOS XE Software for Cisco Catalyst 9800 Series Wireless Controllers could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper validation of parameters in a Flexible NetFlow Version 9 record. An attacker could exploit this vulnerability by sending a malformed Flexible NetFlow Version 9 packet to the Control and Provisioning of Wireless Access Points (CAPWAP) data port of an affected device. An exploit could allow the attacker to trigger an infinite loop, resulting in a process crash that would cause a reload of the device.","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-20"],"references":["https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-fnfv9-dos-HND6Fc9u","https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-fnfv9-dos-HND6Fc9u"],"products":["cisco:ios_xe"],"source":"nvd","synced_at":"2026-10-19T21:05:42.039641217+00:00"},"epss":{"cve":"CVE-2020-3221","score":0.0151,"percentile":0.74443,"date":"2026-11-01"},"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."]}