{"cve":"CVE-2020-3479","nvd":{"published":"2020-09-24T18:15:20.010","modified":"2026-06-17T03:18:23.077","status":"Modified","description":"A vulnerability in the implementation of Multiprotocol Border Gateway Protocol (MP-BGP) for the Layer 2 VPN (L2VPN) Ethernet VPN (EVPN) address family in Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to incorrect processing of Border Gateway Protocol (BGP) update messages that contain crafted EVPN attributes. An attacker could exploit this vulnerability by sending BGP update messages with specific, malformed attributes to an affected device. A successful exploit could allow the attacker to cause an affected device to crash, resulting in a DoS condition.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-400","CWE-20"],"references":["https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ios-bgp-evpn-dos-LNfYJxfF","https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ios-bgp-evpn-dos-LNfYJxfF"],"products":["cisco:ios","cisco:ios_xe"],"source":"nvd","synced_at":"2026-10-19T21:09:53.489947993+00:00"},"epss":{"cve":"CVE-2020-3479","score":0.01097,"percentile":0.65618,"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."]}