{"id":"CVE-2020-3397","aliases":["EUVD-2020-24668","GHSA-5799-w2pr-v9hg"],"status":"published","title":"Cisco NX-OS Software Border Gateway Protocol Multicast VPN Denial of Service Vulnerability","description":"A vulnerability in the Border Gateway Protocol (BGP) Multicast VPN (MVPN) implementation of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause an affected device to unexpectedly reload, resulting in a denial of service (DoS) condition. The vulnerability is due to incomplete input validation of a specific type of BGP MVPN update message. An attacker could exploit this vulnerability by sending this specific, valid BGP MVPN update message to a targeted device. A successful exploit could allow the attacker to cause one of the BGP-related routing applications to restart multiple times, leading to a system-level restart. Note: The Cisco implementation of BGP accepts incoming BGP traffic from only explicitly configured peers. To exploit this vulnerability, an attacker must send a specific BGP MVPN update message over an established TCP connection that appears to come from a trusted BGP peer. To do so, the attacker must obtain information about the BGP peers in the trusted network of the affected system.","severity":{"version":"3.0","score":8.6,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.01812,"percentile":0.78794,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-20"],"published":"2020-08-27T15:40:34Z","modified":"2026-06-17T03:18:10Z","products":[{"vendor":"cisco","product":"cisco nx-os software"},{"vendor":"cisco","product":"nx-os"}],"references":[{"url":"https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxosbgp-nlri-dos-458rG2OQ","tags":["vendor-advisory","x_refsource_CISCO","x_transferred","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-3397"},{"url":"https://github.com/advisories/GHSA-5799-w2pr-v9hg"}],"sources":{"cve":[{"id":"CVE-2020-3397","title":"Cisco NX-OS Software Border Gateway Protocol Multicast VPN Denial of Service Vulnerability","description":"A vulnerability in the Border Gateway Protocol (BGP) Multicast VPN (MVPN) implementation of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause an affected device to unexpectedly reload, resulting in a denial of service (DoS) condition. The vulnerability is due to incomplete input validation of a specific type of BGP MVPN update message. An attacker could exploit this vulnerability by sending this specific, valid BGP MVPN update message to a targeted device. A successful exploit could allow the attacker to cause one of the BGP-related routing applications to restart multiple times, leading to a system-level restart. Note: The Cisco implementation of BGP accepts incoming BGP traffic from only explicitly configured peers. To exploit this vulnerability, an attacker must send a specific BGP MVPN update message over an established TCP connection that appears to come from a trusted BGP peer. To do so, the attacker must obtain information about the BGP peers in the trusted network of the affected system.","status":"published","published":"2020-08-27T15:40:34.148Z","modified":"2024-11-13T18:09:56.819Z","cvss":[{"version":"3.0","score":8.6,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-20"],"updated_at":"2026-11-02T14:35:51.923913Z"}],"euvd":[{"id":"EUVD-2020-24668","description":"A vulnerability in the Border Gateway Protocol (BGP) Multicast VPN (MVPN) implementation of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause an affected device to unexpectedly reload, resulting in a denial of service (DoS) condition. The vulnerability is due to incomplete input validation of a specific type of BGP MVPN update message. An attacker could exploit this vulnerability by sending this specific, valid BGP MVPN update message to a targeted device. A successful exploit could allow the attacker to cause one of the BGP-related routing applications to restart multiple times, leading to a system-level restart. Note: The Cisco implementation of BGP accepts incoming BGP traffic from only explicitly configured peers. To exploit this vulnerability, an attacker must send a specific BGP MVPN update message over an established TCP connection that appears to come from a trusted BGP peer. To do so, the attacker must obtain information about the BGP peers in the trusted network of the affected system.","status":"published","published":"2020-08-27T15:40:34Z","modified":"2024-11-13T18:09:56Z","cvss":[{"version":"3.0","score":8.6,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-03T00:05:01.673157Z"}],"ghsa":[{"id":"GHSA-5799-w2pr-v9hg","title":"A vulnerability in the Border Gateway Protocol (BGP) Multicast VPN (MVPN) implementation of Cisco...","description":"A vulnerability in the Border Gateway Protocol (BGP) Multicast VPN (MVPN) implementation of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause an affected device to unexpectedly reload, resulting in a denial of service (DoS) condition. The vulnerability is due to incomplete input validation of a specific type of BGP MVPN update message. An attacker could exploit this vulnerability by sending this specific, valid BGP MVPN update message to a targeted device. A successful exploit could allow the attacker to cause one of the BGP-related routing applications to restart multiple times, leading to a system-level restart. Note: The Cisco implementation of BGP accepts incoming BGP traffic from only explicitly configured peers. To exploit this vulnerability, an attacker must send a specific BGP MVPN update message over an established TCP connection that appears to come from a trusted BGP peer. To do so, the attacker must obtain information about the BGP peers in the trusted network of the affected system.","status":"published","published":"2022-05-24T17:26:51Z","modified":"2023-01-29T05:04:18Z","cwes":["CWE-20"],"updated_at":"2026-11-02T14:45:31.23097Z"}],"nvd":[{"id":"CVE-2020-3397","description":"A vulnerability in the Border Gateway Protocol (BGP) Multicast VPN (MVPN) implementation of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause an affected device to unexpectedly reload, resulting in a denial of service (DoS) condition. The vulnerability is due to incomplete input validation of a specific type of BGP MVPN update message. An attacker could exploit this vulnerability by sending this specific, valid BGP MVPN update message to a targeted device. A successful exploit could allow the attacker to cause one of the BGP-related routing applications to restart multiple times, leading to a system-level restart. Note: The Cisco implementation of BGP accepts incoming BGP traffic from only explicitly configured peers. To exploit this vulnerability, an attacker must send a specific BGP MVPN update message over an established TCP connection that appears to come from a trusted BGP peer. To do so, the attacker must obtain information about the BGP peers in the trusted network of the affected system.","status":"published","published":"2020-08-27T16:15:12.143Z","modified":"2026-06-17T03:18:10.517Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"primary"},{"version":"3.0","score":8.6,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"secondary"},{"version":"2.0","score":7.1,"vector":"AV:N/AC:M/Au:N/C:N/I:N/A:C","level":"high","assessor":"primary"}],"cwes":["CWE-20"],"updated_at":"2026-11-02T14:06:13.600965Z"}]}}