{"id":"CVE-2021-1440","aliases":["EUVD-2021-6907","GHSA-g8j6-3mwg-7x4g"],"status":"published","title":"Cisco IOS XR Software BGP Resource Public Key Infrastructure Denial of Service Vulnerability","description":"A vulnerability in the implementation of the Resource Public Key Infrastructure (RPKI) feature of Cisco\u0026nbsp;IOS XR Software could allow an unauthenticated, remote attacker to cause the Border Gateway Protocol (BGP) process to crash, resulting in a denial of service (DoS) condition.\r\nThis vulnerability is due to the incorrect handling of a specific RPKI to Router (RTR) Protocol packet header. An attacker could exploit this vulnerability by compromising the RPKI validator server and sending a specifically crafted RTR packet to an affected device. Alternatively, the attacker could use man-in-the-middle techniques to impersonate the RPKI validator server and send a specifically crafted RTR response packet over the established RTR TCP connection to the affected device. A successful exploit could allow the attacker to cause a DoS condition because the BGP process could constantly restart and BGP routing could become unstable.Cisco\u0026nbsp;has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.This advisory is part of the September 2021 release of the Cisco\u0026nbsp;IOS XR Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see .","severity":{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00805,"percentile":0.57076,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-617"],"published":"2024-11-18T15:34:27Z","modified":"2026-06-17T03:31:47Z","products":[{"vendor":"cisco","product":"cisco ios xr software"},{"vendor":"cisco","product":"ios_xr"}],"references":[{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-xrbgp-rpki-dos-gvmjqxbk","tags":["Vendor Advisory"]},{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-xss-webui-gQLSFyPM","tags":["Not Applicable"]},{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-sigverbypass-gPYXd6Mk","tags":["Not Applicable"]},{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-esa-sma-info-disclo-VOu2GHbZ","tags":["Not Applicable"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-1440"},{"url":"https://github.com/advisories/GHSA-g8j6-3mwg-7x4g"}],"sources":{"cve":[{"id":"CVE-2021-1440","title":"Cisco IOS XR Software BGP Resource Public Key Infrastructure Denial of Service Vulnerability","description":"A vulnerability in the implementation of the Resource Public Key Infrastructure (RPKI) feature of Cisco\u0026nbsp;IOS XR Software could allow an unauthenticated, remote attacker to cause the Border Gateway Protocol (BGP) process to crash, resulting in a denial of service (DoS) condition.\r\nThis vulnerability is due to the incorrect handling of a specific RPKI to Router (RTR) Protocol packet header. An attacker could exploit this vulnerability by compromising the RPKI validator server and sending a specifically crafted RTR packet to an affected device. Alternatively, the attacker could use man-in-the-middle techniques to impersonate the RPKI validator server and send a specifically crafted RTR response packet over the established RTR TCP connection to the affected device. A successful exploit could allow the attacker to cause a DoS condition because the BGP process could constantly restart and BGP routing could become unstable.Cisco\u0026nbsp;has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.This advisory is part of the September 2021 release of the Cisco\u0026nbsp;IOS XR Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see .","status":"published","published":"2024-11-18T15:34:27.378Z","modified":"2024-11-18T15:51:25.688Z","cvss":[{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"medium","assessor":"cna"}],"cwes":["CWE-617"],"updated_at":"2026-11-02T14:33:08.811269Z"}],"euvd":[{"id":"EUVD-2021-6907","description":"A vulnerability in the implementation of the Resource Public Key Infrastructure (RPKI) feature of Cisco\u0026nbsp;IOS XR Software could allow an unauthenticated, remote attacker to cause the Border Gateway Protocol (BGP) process to crash, resulting in a denial of service (DoS) condition.\r\nThis vulnerability is due to the incorrect handling of a specific RPKI to Router (RTR) Protocol packet header. An attacker could exploit this vulnerability by compromising the RPKI validator server and sending a specifically crafted RTR packet to an affected device. Alternatively, the attacker could use man-in-the-middle techniques to impersonate the RPKI validator server and send a specifically crafted RTR response packet over the established RTR TCP connection to the affected device. A successful exploit could allow the attacker to cause a DoS condition because the BGP process could constantly restart and BGP routing could become unstable.Cisco\u0026nbsp;has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.This advisory is part of the September 2021 release of the Cisco\u0026nbsp;IOS XR Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see .","status":"published","published":"2024-11-18T15:34:27Z","modified":"2024-11-18T15:51:25Z","cvss":[{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-03T00:04:57.054288Z"}],"ghsa":[{"id":"GHSA-g8j6-3mwg-7x4g","title":"A vulnerability in the implementation of the Resource Public Key Infrastructure (RPKI) feature of...","description":"A vulnerability in the implementation of the Resource Public Key Infrastructure (RPKI) feature of Cisco\u0026nbsp;IOS XR Software could allow an unauthenticated, remote attacker to cause the Border Gateway Protocol (BGP) process to crash, resulting in a denial of service (DoS) condition.\nThis vulnerability is due to the incorrect handling of a specific RPKI to Router (RTR) Protocol packet header. An attacker could exploit this vulnerability by compromising the RPKI validator server and sending a specifically crafted RTR packet to an affected device. Alternatively, the attacker could use man-in-the-middle techniques to impersonate the RPKI validator server and send a specifically crafted RTR response packet over the established RTR TCP connection to the affected device. A successful exploit could allow the attacker to cause a DoS condition because the BGP process could constantly restart and BGP routing could become unstable.Cisco\u0026nbsp;has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.This advisory is part of the September 2021 release of the Cisco\u0026nbsp;IOS XR Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see .","status":"published","published":"2024-11-18T18:30:57Z","modified":"2025-08-01T18:31:10Z","cvss":[{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-617"],"updated_at":"2026-11-02T15:03:10.193177Z"}],"nvd":[{"id":"CVE-2021-1440","description":"A vulnerability in the implementation of the Resource Public Key Infrastructure (RPKI) feature of Cisco\u0026nbsp;IOS XR Software could allow an unauthenticated, remote attacker to cause the Border Gateway Protocol (BGP) process to crash, resulting in a denial of service (DoS) condition.\r\nThis vulnerability is due to the incorrect handling of a specific RPKI to Router (RTR) Protocol packet header. An attacker could exploit this vulnerability by compromising the RPKI validator server and sending a specifically crafted RTR packet to an affected device. Alternatively, the attacker could use man-in-the-middle techniques to impersonate the RPKI validator server and send a specifically crafted RTR response packet over the established RTR TCP connection to the affected device. A successful exploit could allow the attacker to cause a DoS condition because the BGP process could constantly restart and BGP routing could become unstable.Cisco\u0026nbsp;has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.This advisory is part of the September 2021 release of the Cisco\u0026nbsp;IOS XR Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see .","status":"published","published":"2024-11-18T16:15:10.4Z","modified":"2026-06-17T03:31:47.04Z","cvss":[{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"medium","assessor":"secondary"}],"cwes":["CWE-617"],"updated_at":"2026-11-02T14:07:08.629518Z"}]}}