{
  "document": {
    "acknowledgments": [
      {
        "summary": "This vulnerability was found by Mrinmoy Ghosh of Cisco during internal security testing."
      }
    ],
    "category": "csaf_security_advisory",
    "csaf_version": "2.0",
    "notes": [
      {
        "category": "summary",
        "text": "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.\r\n\r\nThe 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\u2019 status. If successful, the attacker could cause the BGP process to restart unexpectedly, resulting in a DoS condition.\r\n\r\nThe 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\u0027s BGP network on an existing, valid TCP connection to a BGP peer.\r\n\r\nCisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.\r\n\r\nThis advisory is available at the following link:\r\nhttps://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200122-ios-xr-routes [\"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200122-ios-xr-routes\"]",
        "title": "Summary"
      },
      {
        "category": "general",
        "text": "The vulnerability affects Cisco devices that are  running a vulnerable release of Cisco IOS XR Software later than 6.6.1 and  are configured for BGP on a device with the L2VPN EVPN address family.\r\n\r\n  Determine Whether the Device Has a Vulnerable Configuration\r\n\r\nTo determine whether the device is configured for BGP, administrators can use the show running-config router bgp  EXEC command in the CLI. If the router is configured for BGP, this  command will return output. The following example shows the partial  output of the show running-config router bgp command on a device that is configured for BGP:\r\n\r\n\r\n\r\n\r\n# show running-config router bgp\r\nrouter bgp 65536\r\n.  .  .\r\n\r\nTo determine whether the device is configured for the EVPN address family, administrators can use the show running-config router bgp AS-Number address-family l2vpn evpn EXEC command in the CLI. If the router is configured for the BGP EVPN address family, this command will return output. The following example shows the partial output of the show running-config router bgp AS-Number address-family l2vpn evpn command on a device with the EVPN address family configured:\r\n\r\n\r\n# show running-config router bgp 65536 address-family l2vpn evpn\r\n  router bgp 100\r\naddress-family l2vpn evpn\r\n.  .  .",
        "title": "Vulnerable Products"
      },
      {
        "category": "general",
        "text": "Only products listed in the Vulnerable Products [\"#vp\"] section of this advisory are known to be affected by this vulnerability.\r\n\r\nCisco has confirmed that this vulnerability does not affect Cisco IOS Software, Cisco IOS XE Software, or Cisco NX-OS Software.",
        "title": "Products Confirmed Not Vulnerable"
      },
      {
        "category": "general",
        "text": "Ethernet VPN (EVPN) is a next-generation solution that provides Ethernet  multipoint services over Multiprotocol Label Switching (MPLS) networks. Customers can learn more about  EVPN and configuration options in L2VPN and Ethernet Services Configuration Guide for Cisco ASR 9000 Series Routers [\"https://www.cisco.com/c/en/us/td/docs/routers/asr9000/software/asr9k-r7-0/lxvpn/configuration/guide/b-l2vpn-cg-asr9000-70x/b-l2vpn-cg-asr9000-70x_chapter_01011.html\"] and in guides for other platforms that support this feature.",
        "title": "Details"
      },
      {
        "category": "general",
        "text": "There are no workarounds that address this vulnerability.",
        "title": "Workarounds"
      },
      {
        "category": "general",
        "text": "Cisco has released free software updates that address the vulnerability described in this advisory. Customers may only install and expect support for software versions and feature sets for which they have purchased a license. By installing, downloading, accessing, or otherwise using such software upgrades, customers agree to follow the terms of the Cisco software license:\r\nhttps://www.cisco.com/c/en/us/products/end-user-license-agreement.html [\"https://www.cisco.com/c/en/us/products/end-user-license-agreement.html\"]\r\n\r\nAdditionally, customers may only download software for which they have a valid license, procured from Cisco directly, or through a Cisco authorized reseller or partner. In most cases this will be a maintenance upgrade to software that was previously purchased. Free security software updates do not entitle customers to a new software license, additional software feature sets, or major revision upgrades.\r\n\r\nWhen considering software upgrades [\"https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html#fixes\"], customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories and Alerts page [\"https://www.cisco.com/go/psirt\"], to determine exposure and a complete upgrade solution.\r\n\r\nIn all cases, customers should ensure that the devices to be upgraded contain sufficient memory and confirm that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, customers are advised to contact the Cisco Technical Assistance Center (TAC) or their contracted maintenance providers.\r\n  Customers Without Service Contracts\r\nCustomers who purchase directly from Cisco but do not hold a Cisco service contract and customers who make purchases through third-party vendors but are unsuccessful in obtaining fixed software through their point of sale should obtain upgrades by contacting the Cisco TAC:\r\nhttps://www.cisco.com/c/en/us/support/web/tsd-cisco-worldwide-contacts.html [\"https://www.cisco.com/c/en/us/support/web/tsd-cisco-worldwide-contacts.html\"]\r\n\r\nCustomers should have the product serial number available and be prepared to provide the URL of this advisory as evidence of entitlement to a free upgrade.\r\n  Fixed Releases\r\nCisco will fix this vulnerability in Cisco IOS XR Software Releases 6.63, 7.02, and 7.1.1.\r\n\r\nAt the time of publication, the SMUs in the following table were  available. Customers who require SMUs for other platforms and releases  are advised to contact their support organization.\r\n                                IOS XR Release              Platform              SMU Name1\r\n                                              6.6.1\r\n              NCS5500\r\n              ncs5500-6.6.1.CSCvr91660\r\n                                  6.6.1\r\n              ASR9K-X64\r\n              asr9k-x64-6.6.1.CSCvr91660\r\n                                  6.6.1\r\n              NCS540\r\n              ncs540-6.6.1.CSCvr91660\r\n                                  6.6.1\r\n              NCS6K\r\n              ncs6k-6.6.1.CSCvr91660\r\n                                  6.6.2\r\n              ASR9K\r\n              asr9k-px-6.6.2.CSCvr91676\r\n                                  6.6.2\r\n              ASR9K-X64              asr9k-x64-6.6.2.CSCvr91676                                  6.6.2\r\n              CRS\r\n                                                 6.6.2\r\n              NCS5K\r\n                                  6.6.2\r\n              XRV9K\r\n              xrv9k-6.6.2.CSCvr91676\r\n                                  6.6.25\r\n              NCS540\r\n\r\n                                  6.6.25              NCS540L                                                 6.6.25              NCS560\r\n              ncs560-6.6.25.CSCvr91676\r\n                                  6.6.25\r\n              NCS5500\r\n              ncs5500-6.6.25.CSCvr91676\r\n                                  7.0.1\r\n              ASR9K-X64              asr9k-x64-7.0.1.CSCvr91676                                  7.0.1              NCS1K                                                 7.0.1              NCS5K\r\n                                  7.0.1              NCS6K\r\n\r\n                                  7.0.1              NCS540\r\n                                                 7.0.1              NCS540L\r\n\r\n                                  7.0.1              NCS560\r\n\r\n                                  7.0.1              NCS5500\r\n                                  7.0.1              XRV9K\r\n\r\n1. Fixes for the vulnerability described in this advisory were provided in the fix for CSCvr91660 and CSCvr91676.\r\n\r\nCSCvr91660 includes the fixes for CSCvr84254, CSCvr74986, CSCvr74413, CSCvr80793, CSCvr83742, CSCvr74902, CSCvo90073, and CSCvr69950.\r\n\r\nCSCvr91676 includes the fixes for CSCvr84254, CSCvr74986, CSCvr74413, CSCvr80793, CSCvr83742, CSCvr74902, and CSCvr69950.\r\n\r\n  Customers can download the SMUs from the Software Center [\"https://software.cisco.com/download/home\"] on Cisco.com by doing the following:\r\n\r\nClick Browse All.\r\nChoose IOS and NX-OS Software \u003e IOS XR \u003e IOS XR Software \u003e Optical Networking or Routers.\r\nChoose the appropriate product and model.\r\nAccess releases by using the left pane of the appropriate product page.",
        "title": "Fixed Software"
      },
      {
        "category": "general",
        "text": "To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy [\"https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html\"]. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.",
        "title": "Vulnerability Policy"
      },
      {
        "category": "general",
        "text": "The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.",
        "title": "Exploitation and Public Announcements"
      },
      {
        "category": "general",
        "text": "This vulnerability was found by Mrinmoy Ghosh of Cisco during internal security testing.",
        "title": "Source"
      },
      {
        "category": "legal_disclaimer",
        "text": "THIS DOCUMENT IS PROVIDED ON AN \"AS IS\" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME.\r\n\r\nA standalone copy or paraphrase of the text of this document that omits the distribution URL is an uncontrolled copy and may lack important information or contain factual errors. The information in this document is intended for end users of Cisco products.",
        "title": "Legal Disclaimer"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "Emergency Support:\r\n+1 877 228 7302 (toll-free within North America)\r\n+1 408 525 6532 (International direct-dial)\r\nNon-emergency Support:\r\nEmail: psirt@cisco.com\r\nSupport requests that are received via e-mail are typically acknowledged within 48 hours.",
      "issuing_authority": "Cisco product security incident response is the responsibility of the Cisco Product Security Incident Response Team (PSIRT). The Cisco PSIRT is a dedicated, global team that manages the receipt, investigation, and public reporting of security vulnerability information that is related to Cisco products and networks. The on-call Cisco PSIRT works 24x7 with Cisco customers, independent security researchers, consultants, industry organizations, and other vendors to identify possible security issues with Cisco products and networks.\r\nMore information can be found in Cisco Security Vulnerability Policy available at https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html",
      "name": "Cisco",
      "namespace": "https://wwww.cisco.com"
    },
    "references": [
      {
        "category": "self",
        "summary": "Cisco IOS XR Software BGP EVPN Operational Routes Denial of Service Vulnerability",
        "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200122-ios-xr-routes"
      },
      {
        "category": "external",
        "summary": "Cisco Security Vulnerability Policy",
        "url": "https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html"
      },
      {
        "category": "external",
        "summary": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200122-ios-xr-routes",
        "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200122-ios-xr-routes"
      },
      {
        "category": "external",
        "summary": "L2VPN and Ethernet Services Configuration Guide for Cisco ASR 9000 Series Routers",
        "url": "https://www.cisco.com/c/en/us/td/docs/routers/asr9000/software/asr9k-r7-0/lxvpn/configuration/guide/b-l2vpn-cg-asr9000-70x/b-l2vpn-cg-asr9000-70x_chapter_01011.html"
      },
      {
        "category": "external",
        "summary": "https://www.cisco.com/c/en/us/products/end-user-license-agreement.html",
        "url": "https://www.cisco.com/c/en/us/products/end-user-license-agreement.html"
      },
      {
        "category": "external",
        "summary": "considering software upgrades",
        "url": "https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html#fixes"
      },
      {
        "category": "external",
        "summary": "Cisco Security Advisories and Alerts page",
        "url": "https://www.cisco.com/go/psirt"
      },
      {
        "category": "external",
        "summary": "https://www.cisco.com/c/en/us/support/web/tsd-cisco-worldwide-contacts.html",
        "url": "https://www.cisco.com/c/en/us/support/web/tsd-cisco-worldwide-contacts.html"
      },
      {
        "category": "external",
        "summary": "Software Center",
        "url": "https://software.cisco.com/download/home"
      },
      {
        "category": "external",
        "summary": "Security Vulnerability Policy",
        "url": "https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html"
      }
    ],
    "title": "Cisco IOS XR Software BGP EVPN Operational Routes Denial of Service Vulnerability",
    "tracking": {
      "current_release_date": "2020-01-24T16:22:50+00:00",
      "generator": {
        "date": "2022-09-03T02:59:29+00:00",
        "engine": {
          "name": "TVCE"
        }
      },
      "id": "cisco-sa-20200122-ios-xr-routes",
      "initial_release_date": "2020-01-22T16:00:00+00:00",
      "revision_history": [
        {
          "date": "2020-01-22T15:55:50+00:00",
          "number": "1.0.0",
          "summary": "Initial public release."
        },
        {
          "date": "2020-01-24T16:22:50+00:00",
          "number": "1.1.0",
          "summary": "Included BGP in advisory title to better identify affected service."
        }
      ],
      "status": "final",
      "version": "1.1.0"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "category": "product_family",
            "name": "Cisco IOS XR Software",
            "product": {
              "name": "Cisco IOS XR Software ",
              "product_id": "CSAFPID-5834"
            }
          }
        ],
        "category": "vendor",
        "name": "Cisco"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2019-16018",
      "ids": [
        {
          "system_name": "Cisco Bug ID",
          "text": "CSCvr74902"
        }
      ],
      "notes": [
        {
          "category": "other",
          "text": "Complete.",
          "title": "Affected Product Comprehensiveness"
        }
      ],
      "product_status": {
        "known_affected": [
          "CSAFPID-5834"
        ]
      },
      "release_date": "2020-01-22T16:00:00+00:00",
      "remediations": [
        {
          "category": "vendor_fix",
          "details": "Cisco has released software updates that address this vulnerability.",
          "product_ids": [
            "CSAFPID-5834"
          ],
          "url": "https://software.cisco.com"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "baseScore": 7.4,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:H",
            "version": "3.0"
          },
          "products": [
            "CSAFPID-5834"
          ]
        }
      ],
      "title": "Cisco IOS XR Software EVPN Operational Routes Denial of Service Vulnerability"
    }
  ]
}