{
  "document": {
    "acknowledgments": [
      {
        "summary": "This vulnerability was found during the resolution of a Cisco TAC support case."
      }
    ],
    "category": "csaf_security_advisory",
    "csaf_version": "2.0",
    "notes": [
      {
        "category": "summary",
        "text": "A vulnerability in the implementation of the Intermediate System-to-Intermediate System (IS-IS) routing protocol functionality in Cisco IOS XR Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition in the IS-IS process.\r\n\r\nThe vulnerability is due to improper handling of a Simple Network Management Protocol (SNMP) request for specific Object Identifiers (OIDs) by the  IS-IS process. An attacker could exploit this vulnerability by sending a crafted SNMP request to the affected device. A successful exploit could allow the attacker to cause a DoS condition in the  IS-IS process.\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-dos [\"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200122-ios-xr-dos\"]",
        "title": "Summary"
      },
      {
        "category": "general",
        "text": "This vulnerability affects Cisco devices if they are running Cisco IOS XR Software releases earlier than 6.6.3, 7.0.2, 7.1.1, or 7.2.1 and they configured with both the IS-IS routing protocol and SNMP versions 1, 2c, or 3.\r\n\r\nCisco has confirmed that this vulnerability affects both Cisco IOS XR 32-bit Software and Cisco IOS XR 64-bit Software.\r\n  Determine Whether the Device Has a Vulnerable Configuration\r\nTo determine if the device is configured for IS-IS routing, administrators can use the show running-config router isis EXEC command in the CLI. If the device is configured for IS-IS routing, this command will return output. The following example shows the partial output of the  show running-config router isis command on a device that is configured for IS-IS routing.\r\n\r\n\r\n#show running-config router isis\r\nrouter isis {isp}  is-type level-2-only  ...\r\n\r\nTo determine if the device is configured for SNMP, administrators can use the show running-config snmp EXEC command in the CLI. If the device is configured for SNMP, this command will return output. The following examples show the partial output of the show running-config  snmp command on a device that is configured for SNMP. Only one version of SNMP needs to be configured for the device to be vulnerable. The vulnerability is triggered through an SNMP query, but the configuration can be for read or write.\r\n\r\nSNMPv1\r\n\r\n\r\n#show running-config snmp\r\nsnmp-server community {public ro}  ...\r\n\r\nSNMPv2\r\n\r\n\r\n#show running-config snmp\r\nsnmp-server group {SNMP_GROUP1} v2c  ...\r\n\r\nSNMPv3\r\n\r\n\r\n#show running-config snmp\r\nsnmp-server view {SNMP_VIEW1 1.3.6.1.2.1.1.5 included}  snmp-server group {SNMP_GROUP1} v3 {auth read SNMP_VIEW1}  ...",
        "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 the following Cisco products:\r\n\r\nCisco IOS and IOS XE Software\r\nCisco IOS XR7-LNT Software\r\nCisco NX-OS Software",
        "title": "Products Confirmed Not Vulnerable"
      },
      {
        "category": "general",
        "text": "There are no workarounds that address this vulnerability. However, administrators may choose to perform one of the following mitigations:\r\n\r\nDisable SNMP: This vulnerability is exploited by doing an SNMP query of a special MIB OID range. If SNMP is disabled, this vulnerability cannot be exploited. For mitigation of this vulnerability if SNMP is enabled on the device, contact Cisco TAC for assistance with the OIDs.\r\n\r\nConfigure an access control list: Administrators can also configure an access control list (ACL) on an SNMP community to filter incoming SNMP requests to ensure that SNMP queries are performed only by trusted SNMP clients. For information about configuring ACLs, see the  Cisco Guide to Harden Cisco IOS XR Devices [\"https://sec.cloudapps.cisco.com/security/center/resources/increase_security_ios_xr_devices.html#28\"].",
        "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 fixed this vulnerability in Cisco IOS XR Software Release 6.6.3. Cisco also plans to fix this vulnerability in Cisco IOS XR Software releases  7.0.2, 7.1.1, and 7.2.1.\r\n\r\nCustomers are advised to install the appropriate SMU as shown in the following table. Customers who require SMUs for other platforms and releases are advised to contact their support organization.\r\n                                IOS XR Release              Platform              SMU Name                                              4.3.2              XR12000               c12k-4.3.2.CSCvr62342\r\n                                  5.2.5\r\n              NCS6K\r\n              ncs6k-5.2.5.CSCvr62342\r\n                                  6.1.2\r\n              ASR9K-PX\r\n              asr9k-px-6.1.2.CSCvr62342\r\n                                  6.1.3\r\n              ASR9K-PX\r\n              asr9k-px-6.1.3.CSCvr62342\r\n                                  6.1.3\r\n              NCS5K\r\n              ncs5k-6.1.3.CSCvr62342\r\n                                  6.1.3\r\n              NCS5500\r\n              ncs5500-6.1.3.CSCvr62342\r\n                                  6.1.4\r\n              ASR9K-PX\r\n              asr9k-px-6.1.4.CSCvr6234\r\n                                  6.1.4\r\n              CRS-PX\r\n              hfr-px-6.1.4.CSCvr62342\r\n                                  6.1.4\r\n              NCS5500\r\n              ncs5500-6.1.4.CSCvr62342\r\n                                  6.1.4\r\n              NCS5K\r\n              ncs5k-6.1.4.CSCvr62342\r\n                                  6.1.4\r\n              XRV9K\r\n              xrv9k-6.1.4.CSCvr62342\r\n                                  6.2.2\r\n              ASR9K-PX\r\n              asr9k-px-6.2.2.CSCvr62342\r\n                                  6.2.2\r\n              NCS6K\r\n              ncs6k-6.2.2.CSCvr62342\r\n                                  6.2.25\r\n              NCS5K\r\n              ncs5k-6.2.25.CSCvr62342\r\n                                  6.2.25\r\n              NCS6K\r\n              ncs6k-6.2.25.CSCvr62342\r\n                                  6.2.3\r\n              NCS5K\r\n              ncs5k-6.2.3.CSCvr62342\r\n                                  6.2.3\r\n              ASR9K-PX\r\n               asr9k-px-6.2.3.CSCvr62342\r\n                                  6.2.3\r\n              ASR9K-X64\r\n              asr9k-x64-6.2.3.CSCvr62342\r\n                                  6.2.3\r\n              CRS-PX\r\n               hfr-px-6.2.3.CSCvr62342\r\n                                  6.2.3\r\n              NCS5500\r\n               ncs5500-6.2.3.CSCvr62342\r\n                                  6.2.3\r\n              XRV9K\r\n              xrv9k-6.2.3.CSCvr62342\r\n                                  6.2.3\r\n              NCS6K\r\n               ncs6k-6.2.3.CSCvr62342\r\n                                  6.3.15\r\n              NCS5500\r\n              ncs5500-6.3.15.CSCvr62342\r\n                                  6.3.2\r\n              ASR9K-PX\r\n              asr9k-px-6.3.2.CSCvr62342\r\n                                  6.3.2\r\n              ASR9K-X64\r\n              asr9k-x64-6.3.2.CSCvr62342\r\n                                  6.3.3\r\n              ASR9K-X64\r\n              asr9k-x64-6.3.3.CSCvr62342\r\n                                  6.3.3\r\n              ASR9K-PX\r\n              asr9k-px-6.3.3.CSCvr62342                                  6.3.3\r\n              NCS5K\r\n              ncs5k-6.3.3.CSCvr62342\r\n                                  6.3.3\r\n              NCS540\r\n              ncs540-6.3.3.CSCvr62342\r\n                                  6.3.3\r\n              NCS5500\r\n              ncs5500-6.3.3.CSCvr62342                                  6.3.3              NCS6K              ncs6k-6.3.3.CSCvr62342                                   6.4.2\r\n              ASR9K-PX\r\n              asr9k-px-6.4.2.CSCvr62342\r\n                                  6.4.2\r\n              ASR9K-X64\r\n              asr9k-x64-6.4.2.CSCvr62342\r\n                                  6.4.2\r\n              CRS-PX\r\n              hfr-px-6.4.2.CSCvr62342\r\n                                  6.4.2\r\n              NCS5K\r\n              ncs5k-6.4.2.CSCvr62342\r\n                                  6.4.2\r\n              NCS6K\r\n              ncs6k-6.4.2.CSCvr62342\r\n                                  6.4.2\r\n              XRV9K\r\n              xrv9k-6.4.2.CSCvr62342\r\n                                  6.5.2\r\n              ASR9K-PX\r\n              asr9k-px-6.5.2.CSCvr62342\r\n                                  6.5.2\r\n              ASR9K-X64\r\n               asr9k-x64-6.5.2.CSCvr62342\r\n                                  6.5.2\r\n              NCS5K\r\n               ncs5k-6.5.2.CSCvr62342\r\n                                  6.5.2\r\n              NCS5500\r\n               ncs5500-6.5.2.CSCvr62342\r\n                                  6.5.3\r\n              ASR9K-X64\r\n              asr9k-x64-6.5.3.CSCvr62342\r\n                                  6.5.3\r\n              NCS5500\r\n              ncs5500-6.5.3.CSCvr62342\r\n                                  6.5.3\r\n              NCS540\r\n              ncs540-6.5.3.CSCvr62342\r\n                                  6.5.3\r\n              NCS5K\r\n              ncs5k-6.5.3.CSCvr62342\r\n                                  6.5.3\r\n              ASR9K-PX\r\n              asr9k-px-6.5.3.CSCvr62342\r\n                                  6.5.3\r\n              XRV9K\r\n              xrv9k-6.5.3.CSCvr62342\r\n                                  6.6.1\r\n              NCS5500\r\n              ncs5500-6.6.1.CSCvr62342\r\n                                  6.6.2\r\n              ASR9K-PX\r\n              asr9k-px-6.6.2.CSCvr62342\r\n                                  6.6.2\r\n              ASR9K-X64\r\n              asr9k-x64-6.6.2.CSCvr62342\r\n                                  6.6.2\r\n              XRV9K\r\n              xrv9k-6.6.2.CSCvr62342\r\n                                  6.6.25\r\n              NCS5500\r\n              ncs5500-6.6.25.CSCvr62342\r\n                                  6.6.25\r\n              NCS540\r\n              ncs540-6.6.25.CSCvr62342\r\n                                  6.6.25              NCS560\r\n              ncs560-6.6.25.CSCvr62342\r\n\r\nTo download the SMUs from the Software Center [\"https://software.cisco.com/download/home\"] on Cisco.com [\"http://cisco.com/\"], do 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 a specific product and model from the right pane of the product selector.\r\nChoose a release from the left pane of the 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 during the resolution of a Cisco TAC support case.",
        "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 Intermediate System-to-Intermediate System Denial of Service Vulnerability",
        "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200122-ios-xr-dos"
      },
      {
        "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-dos",
        "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200122-ios-xr-dos"
      },
      {
        "category": "external",
        "summary": "Cisco Guide to Harden Cisco IOS XR Devices",
        "url": "https://sec.cloudapps.cisco.com/security/center/resources/increase_security_ios_xr_devices.html#28"
      },
      {
        "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": "Cisco.com",
        "url": "http://cisco.com/"
      },
      {
        "category": "external",
        "summary": "Security Vulnerability Policy",
        "url": "https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html"
      }
    ],
    "title": "Cisco IOS XR Software Intermediate System-to-Intermediate System Denial of Service Vulnerability",
    "tracking": {
      "current_release_date": "2020-02-19T18:42:41+00:00",
      "generator": {
        "date": "2022-09-03T03:02:16+00:00",
        "engine": {
          "name": "TVCE"
        }
      },
      "id": "cisco-sa-20200122-ios-xr-dos",
      "initial_release_date": "2020-01-22T16:00:00+00:00",
      "revision_history": [
        {
          "date": "2020-01-22T15:55:51+00:00",
          "number": "1.0.0",
          "summary": "Initial public release."
        },
        {
          "date": "2020-02-04T18:33:40+00:00",
          "number": "1.1.0",
          "summary": "Changed en dashes to hyphens throughout. No content changes were made."
        },
        {
          "date": "2020-02-19T18:42:41+00:00",
          "number": "1.2.0",
          "summary": "Updated Fixed Releases table to add current SMUs."
        }
      ],
      "status": "final",
      "version": "1.2.0"
    }
  },
  "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-2019-16027",
      "ids": [
        {
          "system_name": "Cisco Bug ID",
          "text": "CSCvr62342"
        }
      ],
      "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": 7.7,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H",
            "version": "3.0"
          },
          "products": [
            "CSAFPID-5834"
          ]
        }
      ],
      "title": "Cisco IOS XR Software Intermediate System-to-Intermediate System Denial of Service Vulnerability"
    }
  ]
}