{
  "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 Ethernet over GRE (EoGRE) packet processing of Cisco IOS XE Wireless Controller Software for the Cisco Catalyst 9800 Family Wireless Controller, Embedded Wireless Controller, and Embedded Wireless on Catalyst 9000 Series Switches could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.\r\n\r\nThis vulnerability is due to improper processing of malformed EoGRE packets. An attacker could exploit this vulnerability by sending malicious packets to the affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.\r\n\r\nCisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.\r\n\r\n\r\n\r\nThis advisory is part of the September 2021 release of the Cisco IOS and IOS XE Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: September 2021 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication. [\"https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-74581\"]",
        "title": "Summary"
      },
      {
        "category": "general",
        "text": "This vulnerability affects Cisco IOS XE Wireless Controller Software if the device is running a vulnerable release and has an interface configured with an EoGRE tunnel. The following Cisco products are vulnerable:\r\n\r\nCatalyst 9800 Embedded Wireless Controller for Catalyst 9300, 9400, and 9500 Series Switches\r\nCatalyst 9800 Series Wireless Controllers\r\nCatalyst 9800 Wireless Controller for Cloud\r\nEmbedded Wireless Controller on Catalyst Access Points\r\n\r\nNote: The EoGRE feature is not enabled by default on affected devices. The feature can be enabled on interfaces by using either IPv4 or IPv6.\r\n\r\nFor information about which Cisco software releases are vulnerable, see the Fixed Software [\"#fs\"] section of this advisory.",
        "title": "Vulnerable Products"
      },
      {
        "category": "general",
        "text": "Cisco has confirmed that this vulnerability does not affect the following Cisco products:\r\n\r\nIOS Software\r\nIOS XR Software\r\nMeraki products\r\nNX-OS Software\r\nWireless LAN Controller (WLC) AireOS Software\r\n\r\nOnly products listed in the Vulnerable Products [\"#vp\"] section of this advisory are known to be affected by this vulnerability.",
        "title": "Products Confirmed Not Vulnerable"
      },
      {
        "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 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: https://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        Cisco IOS and IOS XE Software\r\nTo help customers determine their exposure to vulnerabilities in Cisco IOS and IOS XE Software, Cisco provides the Cisco Software Checker [\"https://sec.cloudapps.cisco.com/security/center/softwarechecker.x\"] to identify any Cisco Security Advisories that impact a specific software release and the earliest release that fixes the vulnerabilities described in each advisory (\u201cFirst Fixed\u201d). If applicable, the tool also returns the earliest release that fixes all the vulnerabilities described in all the advisories identified (\u201cCombined First Fixed\u201d).\r\n\r\nCustomers can use the Cisco Software Checker [\"https://sec.cloudapps.cisco.com/security/center/softwarechecker.x\"] to search advisories in the following ways:\r\n\r\nChoose the software and one or more releases\r\nUpload a .txt file that includes a list of specific releases\r\nEnter the output of the show version command\r\n\r\nAfter initiating a search, customers can customize the search to include all Cisco Security Advisories, a specific advisory, or all advisories in the most recent bundled publication.\r\n\r\nCustomers can also use the following form to determine whether a release is affected by any Cisco Security Advisory by entering a Cisco IOS or IOS XE Software release\u2014for example, 15.1(4)M2 or 3.13.8S:\r\n\r\n\r\n\r\nBy default, the Cisco Software Checker [\"https://sec.cloudapps.cisco.com/security/center/softwarechecker.x\"] includes results only for vulnerabilities that have a Critical or High Security Impact Rating (SIR). To include results for Medium SIR vulnerabilities, customers can use the Cisco Software Checker on Cisco.com and check the Medium check box in the drop-down list under Impact Rating when customizing a search.",
        "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": "psirt@cisco.com",
      "issuing_authority": "Cisco PSIRT",
      "name": "Cisco",
      "namespace": "https://wwww.cisco.com"
    },
    "references": [
      {
        "category": "self",
        "summary": "Cisco IOS XE Software for Catalyst 9800 Series Wireless Controllers EoGRE Denial of Service Vulnerability",
        "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ewlc-gre-6u4ELzAT"
      },
      {
        "category": "external",
        "summary": "Cisco Event Response: September 2021 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication",
        "url": "https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-74581"
      },
      {
        "category": "external",
        "summary": "Cisco Security Vulnerability Policy",
        "url": "https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.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\u0026nbsp;Security Advisories 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": "Cisco\u0026nbsp;Software Checker",
        "url": "https://sec.cloudapps.cisco.com/security/center/softwarechecker.x"
      }
    ],
    "title": "Cisco IOS XE Software for Catalyst 9800 Series Wireless Controllers EoGRE Denial of Service Vulnerability",
    "tracking": {
      "current_release_date": "2021-09-22T16:00:00+00:00",
      "generator": {
        "date": "2024-05-10T23:09:12+00:00",
        "engine": {
          "name": "TVCE"
        }
      },
      "id": "cisco-sa-ewlc-gre-6u4ELzAT",
      "initial_release_date": "2021-09-22T16:00:00+00:00",
      "revision_history": [
        {
          "date": "2021-09-22T15:48:25+00:00",
          "number": "1.0.0",
          "summary": "Initial public release."
        }
      ],
      "status": "final",
      "version": "1.0.0"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "branches": [
                  {
                    "category": "service_pack",
                    "name": "16.6.4s",
                    "product": {
                      "name": "16.6.4s",
                      "product_id": "CSAFPID-244900"
                    }
                  }
                ],
                "category": "product_version",
                "name": "16.6"
              },
              {
                "branches": [
                  {
                    "category": "service_pack",
                    "name": "16.10.1",
                    "product": {
                      "name": "16.10.1",
                      "product_id": "CSAFPID-225858"
                    }
                  },
                  {
                    "category": "service_pack",
                    "name": "16.10.1s",
                    "product": {
                      "name": "16.10.1s",
                      "product_id": "CSAFPID-252913"
                    }
                  },
                  {
                    "category": "service_pack",
                    "name": "16.10.1e",
                    "product": {
                      "name": "16.10.1e",
                      "product_id": "CSAFPID-257955"
                    }
                  }
                ],
                "category": "product_version",
                "name": "16.10"
              },
              {
                "branches": [
                  {
                    "category": "service_pack",
                    "name": "16.11.1",
                    "product": {
                      "name": "16.11.1",
                      "product_id": "CSAFPID-227918"
                    }
                  },
                  {
                    "category": "service_pack",
                    "name": "16.11.1a",
                    "product": {
                      "name": "16.11.1a",
                      "product_id": "CSAFPID-252271"
                    }
                  },
                  {
                    "category": "service_pack",
                    "name": "16.11.1b",
                    "product": {
                      "name": "16.11.1b",
                      "product_id": "CSAFPID-260741"
                    }
                  },
                  {
                    "category": "service_pack",
                    "name": "16.11.2",
                    "product": {
                      "name": "16.11.2",
                      "product_id": "CSAFPID-261240"
                    }
                  },
                  {
                    "category": "service_pack",
                    "name": "16.11.1c",
                    "product": {
                      "name": "16.11.1c",
                      "product_id": "CSAFPID-264096"
                    }
                  }
                ],
                "category": "product_version",
                "name": "16.11"
              },
              {
                "branches": [
                  {
                    "category": "service_pack",
                    "name": "16.12.1",
                    "product": {
                      "name": "16.12.1",
                      "product_id": "CSAFPID-227920"
                    }
                  },
                  {
                    "category": "service_pack",
                    "name": "16.12.1s",
                    "product": {
                      "name": "16.12.1s",
                      "product_id": "CSAFPID-265735"
                    }
                  },
                  {
                    "category": "service_pack",
                    "name": "16.12.3",
                    "product": {
                      "name": "16.12.3",
                      "product_id": "CSAFPID-273445"
                    }
                  },
                  {
                    "category": "service_pack",
                    "name": "16.12.2s",
                    "product": {
                      "name": "16.12.2s",
                      "product_id": "CSAFPID-273509"
                    }
                  },
                  {
                    "category": "service_pack",
                    "name": "16.12.1t",
                    "product": {
                      "name": "16.12.1t",
                      "product_id": "CSAFPID-274832"
                    }
                  },
                  {
                    "category": "service_pack",
                    "name": "16.12.2t",
                    "product": {
                      "name": "16.12.2t",
                      "product_id": "CSAFPID-275538"
                    }
                  },
                  {
                    "category": "service_pack",
                    "name": "16.12.4",
                    "product": {
                      "name": "16.12.4",
                      "product_id": "CSAFPID-277147"
                    }
                  },
                  {
                    "category": "service_pack",
                    "name": "16.12.3s",
                    "product": {
                      "name": "16.12.3s",
                      "product_id": "CSAFPID-277255"
                    }
                  },
                  {
                    "category": "service_pack",
                    "name": "16.12.4a",
                    "product": {
                      "name": "16.12.4a",
                      "product_id": "CSAFPID-278881"
                    }
                  },
                  {
                    "category": "service_pack",
                    "name": "16.12.5",
                    "product": {
                      "name": "16.12.5",
                      "product_id": "CSAFPID-280463"
                    }
                  }
                ],
                "category": "product_version",
                "name": "16.12"
              },
              {
                "branches": [
                  {
                    "category": "service_pack",
                    "name": "17.1.1",
                    "product": {
                      "name": "17.1.1",
                      "product_id": "CSAFPID-245377"
                    }
                  },
                  {
                    "category": "service_pack",
                    "name": "17.1.1s",
                    "product": {
                      "name": "17.1.1s",
                      "product_id": "CSAFPID-274818"
                    }
                  },
                  {
                    "category": "service_pack",
                    "name": "17.1.2",
                    "product": {
                      "name": "17.1.2",
                      "product_id": "CSAFPID-277338"
                    }
                  },
                  {
                    "category": "service_pack",
                    "name": "17.1.1t",
                    "product": {
                      "name": "17.1.1t",
                      "product_id": "CSAFPID-277348"
                    }
                  },
                  {
                    "category": "service_pack",
                    "name": "17.1.3",
                    "product": {
                      "name": "17.1.3",
                      "product_id": "CSAFPID-280652"
                    }
                  }
                ],
                "category": "product_version",
                "name": "17.1"
              },
              {
                "branches": [
                  {
                    "category": "service_pack",
                    "name": "17.2.1",
                    "product": {
                      "name": "17.2.1",
                      "product_id": "CSAFPID-251225"
                    }
                  },
                  {
                    "category": "service_pack",
                    "name": "17.2.1a",
                    "product": {
                      "name": "17.2.1a",
                      "product_id": "CSAFPID-277343"
                    }
                  }
                ],
                "category": "product_version",
                "name": "17.2"
              },
              {
                "branches": [
                  {
                    "category": "service_pack",
                    "name": "17.3.1",
                    "product": {
                      "name": "17.3.1",
                      "product_id": "CSAFPID-254712"
                    }
                  },
                  {
                    "category": "service_pack",
                    "name": "17.3.2",
                    "product": {
                      "name": "17.3.2",
                      "product_id": "CSAFPID-277099"
                    }
                  },
                  {
                    "category": "service_pack",
                    "name": "17.3.3",
                    "product": {
                      "name": "17.3.3",
                      "product_id": "CSAFPID-278019"
                    }
                  },
                  {
                    "category": "service_pack",
                    "name": "17.3.2a",
                    "product": {
                      "name": "17.3.2a",
                      "product_id": "CSAFPID-280555"
                    }
                  }
                ],
                "category": "product_version",
                "name": "17.3"
              },
              {
                "branches": [
                  {
                    "category": "service_pack",
                    "name": "17.4.1",
                    "product": {
                      "name": "17.4.1",
                      "product_id": "CSAFPID-262588"
                    }
                  }
                ],
                "category": "product_version",
                "name": "17.4"
              }
            ],
            "category": "product_family",
            "name": "Cisco IOS XE Software"
          }
        ],
        "category": "vendor",
        "name": "Cisco"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2021-1611",
      "ids": [
        {
          "system_name": "Cisco Bug ID",
          "text": "CSCvx48107"
        }
      ],
      "notes": [
        {
          "category": "other",
          "text": "Complete.",
          "title": "Affected Product Comprehensiveness"
        }
      ],
      "product_status": {
        "known_affected": [
          "CSAFPID-225858",
          "CSAFPID-227918",
          "CSAFPID-227920",
          "CSAFPID-244900",
          "CSAFPID-245377",
          "CSAFPID-251225",
          "CSAFPID-252271",
          "CSAFPID-252913",
          "CSAFPID-254712",
          "CSAFPID-257955",
          "CSAFPID-260741",
          "CSAFPID-261240",
          "CSAFPID-262588",
          "CSAFPID-264096",
          "CSAFPID-265735",
          "CSAFPID-273445",
          "CSAFPID-273509",
          "CSAFPID-274818",
          "CSAFPID-274832",
          "CSAFPID-275538",
          "CSAFPID-277099",
          "CSAFPID-277147",
          "CSAFPID-277255",
          "CSAFPID-277338",
          "CSAFPID-277343",
          "CSAFPID-277348",
          "CSAFPID-278019",
          "CSAFPID-278881",
          "CSAFPID-280463",
          "CSAFPID-280555",
          "CSAFPID-280652"
        ]
      },
      "release_date": "2021-09-22T16:00:00+00:00",
      "remediations": [
        {
          "category": "vendor_fix",
          "details": "Cisco has released software updates that address this vulnerability.",
          "product_ids": [
            "CSAFPID-225858",
            "CSAFPID-227918",
            "CSAFPID-227920",
            "CSAFPID-244900",
            "CSAFPID-245377",
            "CSAFPID-251225",
            "CSAFPID-252271",
            "CSAFPID-252913",
            "CSAFPID-254712",
            "CSAFPID-257955",
            "CSAFPID-260741",
            "CSAFPID-261240",
            "CSAFPID-262588",
            "CSAFPID-264096",
            "CSAFPID-265735",
            "CSAFPID-273445",
            "CSAFPID-273509",
            "CSAFPID-274818",
            "CSAFPID-274832",
            "CSAFPID-275538",
            "CSAFPID-277099",
            "CSAFPID-277147",
            "CSAFPID-277255",
            "CSAFPID-277338",
            "CSAFPID-277343",
            "CSAFPID-277348",
            "CSAFPID-278019",
            "CSAFPID-278881",
            "CSAFPID-280463",
            "CSAFPID-280555",
            "CSAFPID-280652"
          ],
          "url": "https://software.cisco.com"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "baseScore": 8.6,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H",
            "version": "3.1"
          },
          "products": [
            "CSAFPID-225858",
            "CSAFPID-227918",
            "CSAFPID-227920",
            "CSAFPID-244900",
            "CSAFPID-245377",
            "CSAFPID-251225",
            "CSAFPID-252271",
            "CSAFPID-252913",
            "CSAFPID-254712",
            "CSAFPID-257955",
            "CSAFPID-260741",
            "CSAFPID-261240",
            "CSAFPID-262588",
            "CSAFPID-264096",
            "CSAFPID-265735",
            "CSAFPID-273445",
            "CSAFPID-273509",
            "CSAFPID-274818",
            "CSAFPID-274832",
            "CSAFPID-275538",
            "CSAFPID-277099",
            "CSAFPID-277147",
            "CSAFPID-277255",
            "CSAFPID-277338",
            "CSAFPID-277343",
            "CSAFPID-277348",
            "CSAFPID-278019",
            "CSAFPID-278881",
            "CSAFPID-280463",
            "CSAFPID-280555",
            "CSAFPID-280652"
          ]
        }
      ],
      "title": "Cisco IOS XE Wireless Controller Software GRE Denial of Service Vulnerability"
    }
  ]
}