{"id":"CVE-2019-16018","aliases":["EUVD-2019-6907","GHSA-638h-mp9x-p4wm"],"status":"published","title":"Cisco IOS XR Software EVPN Operational Routes Denial of Service Vulnerability","description":"A vulnerability in the implementation of Border Gateway Protocol (BGP) Ethernet VPN (EVPN) functionality in Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to incorrect processing of a BGP update message that contains crafted EVPN attributes. An attacker could indirectly exploit the vulnerability by sending BGP EVPN update messages with a specific, malformed attribute to an affected system and waiting for a user on the device to display the EVPN operational routes\u0026rsquo; status. If successful, the attacker could cause the BGP process to restart unexpectedly, resulting in a DoS condition. The Cisco implementation of BGP accepts incoming BGP traffic only from explicitly defined peers. To exploit this vulnerability, the malicious BGP update message would need to come from a configured, valid BGP peer, or would need to be injected by the attacker into the victim's BGP network on an existing, valid TCP connection to a BGP peer.","severity":{"version":"3.0","score":7.4,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-08","score":0.01066,"percentile":0.64988,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-399","CWE-400"],"published":"2020-01-26T04:30:48Z","modified":"2026-06-17T02:21:33Z","products":[{"vendor":"cisco","product":"cisco ios xr software"},{"vendor":"cisco","product":"ios_xr"}],"references":[{"url":"https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200122-ios-xr-routes","tags":["vendor-advisory","x_refsource_CISCO","x_transferred","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2019-16018"},{"url":"https://github.com/advisories/GHSA-638h-mp9x-p4wm"}],"sources":{"cve":[{"id":"CVE-2019-16018","title":"Cisco IOS XR Software EVPN Operational Routes Denial of Service Vulnerability","description":"A vulnerability in the implementation of Border Gateway Protocol (BGP) Ethernet VPN (EVPN) functionality in Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to incorrect processing of a BGP update message that contains crafted EVPN attributes. An attacker could indirectly exploit the vulnerability by sending BGP EVPN update messages with a specific, malformed attribute to an affected system and waiting for a user on the device to display the EVPN operational routes\u0026rsquo; status. If successful, the attacker could cause the BGP process to restart unexpectedly, resulting in a DoS condition. The Cisco implementation of BGP accepts incoming BGP traffic only from explicitly defined peers. To exploit this vulnerability, the malicious BGP update message would need to come from a configured, valid BGP peer, or would need to be injected by the attacker into the victim's BGP network on an existing, valid TCP connection to a BGP peer.","status":"published","published":"2020-01-26T04:30:48.072Z","modified":"2024-11-15T17:46:42.156Z","cvss":[{"version":"3.0","score":7.4,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-399"],"updated_at":"2026-11-02T14:32:23.189113Z"}],"euvd":[{"id":"EUVD-2019-6907","description":"A vulnerability in the implementation of Border Gateway Protocol (BGP) Ethernet VPN (EVPN) functionality in Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to incorrect processing of a BGP update message that contains crafted EVPN attributes. An attacker could indirectly exploit the vulnerability by sending BGP EVPN update messages with a specific, malformed attribute to an affected system and waiting for a user on the device to display the EVPN operational routes\u0026rsquo; status. If successful, the attacker could cause the BGP process to restart unexpectedly, resulting in a DoS condition. The Cisco implementation of BGP accepts incoming BGP traffic only from explicitly defined peers. To exploit this vulnerability, the malicious BGP update message would need to come from a configured, valid BGP peer, or would need to be injected by the attacker into the victim's BGP network on an existing, valid TCP connection to a BGP peer.","status":"published","published":"2020-01-26T04:30:48Z","modified":"2024-11-15T17:46:42Z","cvss":[{"version":"3.0","score":7.4,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-03T00:04:58.20762Z"}],"ghsa":[{"id":"GHSA-638h-mp9x-p4wm","title":"A vulnerability in the implementation of Border Gateway Protocol (BGP) Ethernet VPN (EVPN)...","description":"A vulnerability in the implementation of Border Gateway Protocol (BGP) Ethernet VPN (EVPN) functionality in Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to incorrect processing of a BGP update message that contains crafted EVPN attributes. An attacker could indirectly exploit the vulnerability by sending BGP EVPN update messages with a specific, malformed attribute to an affected system and waiting for a user on the device to display the EVPN operational routes\u0026rsquo; status. If successful, the attacker could cause the BGP process to restart unexpectedly, resulting in a DoS condition. The Cisco implementation of BGP accepts incoming BGP traffic only from explicitly defined peers. To exploit this vulnerability, the malicious BGP update message would need to come from a configured, valid BGP peer, or would need to be injected by the attacker into the victim's BGP network on an existing, valid TCP connection to a BGP peer.","status":"published","published":"2022-05-24T17:07:21Z","modified":"2023-01-29T05:01:11Z","updated_at":"2026-11-02T14:44:45.404949Z"}],"nvd":[{"id":"CVE-2019-16018","description":"A vulnerability in the implementation of Border Gateway Protocol (BGP) Ethernet VPN (EVPN) functionality in Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to incorrect processing of a BGP update message that contains crafted EVPN attributes. An attacker could indirectly exploit the vulnerability by sending BGP EVPN update messages with a specific, malformed attribute to an affected system and waiting for a user on the device to display the EVPN operational routes\u0026rsquo; status. If successful, the attacker could cause the BGP process to restart unexpectedly, resulting in a DoS condition. The Cisco implementation of BGP accepts incoming BGP traffic only from explicitly defined peers. To exploit this vulnerability, the malicious BGP update message would need to come from a configured, valid BGP peer, or would need to be injected by the attacker into the victim's BGP network on an existing, valid TCP connection to a BGP peer.","status":"published","published":"2020-01-26T05:15:14.413Z","modified":"2026-06-17T02:21:33.107Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium","assessor":"primary"},{"version":"3.0","score":7.4,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:H","level":"high","assessor":"secondary"},{"version":"2.0","score":4.3,"vector":"AV:N/AC:M/Au:N/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-399","CWE-400"],"updated_at":"2026-11-02T14:05:43.875329Z"}]}}