{
  "document": {
    "acknowledgments": [
      {
        "summary": "This vulnerability was found during internal security testing."
      }
    ],
    "category": "csaf_security_advisory",
    "csaf_version": "2.0",
    "notes": [
      {
        "category": "summary",
        "text": "A vulnerability in the multicast DNS (mDNS) gateway feature of Cisco Aironet Series Access Points Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device.\r\n\r\nThis vulnerability is due to insufficient input validation of incoming mDNS traffic. An attacker could exploit this vulnerability by sending a crafted mDNS packet to an affected device through a wireless network that is configured in FlexConnect local switching mode or through a wired network on a configured mDNS VLAN. A successful exploit could allow the attacker to cause the access point (AP) to reboot, 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\nThis advisory is available at the following link:\r\nhttps://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-aironet-mdns-dos-E6KwYuMx [\"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-aironet-mdns-dos-E6KwYuMx\"]",
        "title": "Summary"
      },
      {
        "category": "general",
        "text": "This vulnerability affects the following Cisco products if they are running a vulnerable release of Cisco Aironet Series Access Points Software, they have at least one wireless network configured in FlexConnect local switching mode, and the mDNS gateway feature is enabled on the wireless controller for that wireless network or one of the wired VLANs associated to it:\r\n\r\nAironet 1540 Series APs\r\nAironet 1560 Series APs\r\nAironet 1800 Series APs\r\nAironet 2800 Series APs\r\nAironet 3800 Series APs\r\nAironet 4800 APs\r\nCatalyst 9100 APs\r\nCatalyst IW 6300 APs\r\nIntegrated AP on 1100 Integrated Services Routers\r\n6300 Series Embedded Services APs (ESW6300)\r\n  Determine the Status of FlexConnect Local Switching Mode\r\nTo determine whether a wireless network is running in FlexConnect local switching mode, complete the following steps:\r\n\r\nAccess the wireless controller management web interface.\r\nChoose Configuration \u003e Tags \u0026 Profiles \u003e Policy and open the profile that is associated to the wireless network.\r\nIn the General tab, check the status of the Central Switching parameter.\r\n\r\nIf Central Switching is disabled, the network is running in FlexConnect local switching mode\r\n  Determine the Status of the mDNS Gateway feature\r\nTo determine whether the mDNS Gateway is enabled on a wireless network, complete the following steps:\r\n\r\nAccess the wireless controller management web interface.\r\nChoose Configuration \u003e Tags \u0026 Profiles \u003e WLANs and select the wireless network.\r\nOn the Advanced tab, check the value selected in the mDNS Mode drop-down list.\r\n\r\nTo determine whether the mDNS Gateway is enabled on a wired VLAN, complete the following steps:\r\n\r\nAccess the wireless controller management web interface.\r\nChoose Configuration \u003e Services \u003e mDNS.\r\nIn the mDNS Flex Profile section, click the profile name.\r\nCheck the VLANs field to see which VLANs it is enabled for.",
        "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 any Cisco Access Point series that is not listed in the Vulnerable Products [\"#vp\"] section of this advisory.\r\n\r\nCisco has also confirmed that this vulnerability does not affect Cisco Wireless Controller and Cisco Mobility Express because they do not support enabling the mDNS Gateway feature on a FlexConnect wireless network.",
        "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      Fixed Releases\r\nThe process to upgrade the APs requires administrators to upgrade the wireless controller that the APs are registered to.\r\n\r\nCustomers are advised to upgrade to an appropriate fixed software release as indicated in the following table(s). To ensure a complete upgrade solution, consider that this advisory is part of a collection that includes the following advisories:\r\n\r\ncisco-sa-aironet-info-disc-BfWqghj [\"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-aironet-info-disc-BfWqghj\"]: Cisco Aironet Access Points FlexConnect Upgrade Information Disclosure Vulnerability\r\ncisco-sa-aironet-mdns-dos-E6KwYuMx [\"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-aironet-mdns-dos-E6KwYuMx\"]: Cisco Aironet Access Points FlexConnect Multicast DNS Denial of Service Vulnerability\r\ncisco-sa-ap-privesc-wEVfp8Ud [\"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ap-privesc-wEVfp8Ud\"]: Cisco Access Point Software Arbitrary Code Execution Vulnerability\r\n\r\nCisco Access Points Managed by Catalyst 9800 Wireless Controller or Embedded Wireless Controller on Catalyst Access Points\r\n        Cisco Catalyst 9800 Wireless Controller Software Release  First Fixed Release for This Vulnerability  First Fixed Release for All Vulnerabilities Described in This Collection of Advisories          17.2 and earlier  Not vulnerable.  Migrate to a fixed release.      17.3  17.3.3  17.3.3      17.4  Migrate to a fixed release.  17.5.1 (Mar 2021)      17.5 and later  Not vulnerable.  Not vulnerable.\r\nCisco Access Points Managed by Wireless LAN Controller or Mobility Express\r\n\r\nCisco Wireless Controller and Cisco Mobility Express do not support enabling the mDNS Gateway feature on a FlexConnect wireless network, so these access points are not affected by this vulnerability.",
        "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 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 Aironet Access Points FlexConnect Multicast DNS Denial of Service Vulnerability",
        "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-aironet-mdns-dos-E6KwYuMx"
      },
      {
        "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-aironet-mdns-dos-E6KwYuMx",
        "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-aironet-mdns-dos-E6KwYuMx"
      },
      {
        "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-sa-aironet-info-disc-BfWqghj",
        "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-aironet-info-disc-BfWqghj"
      },
      {
        "category": "external",
        "summary": "cisco-sa-aironet-mdns-dos-E6KwYuMx",
        "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-aironet-mdns-dos-E6KwYuMx"
      },
      {
        "category": "external",
        "summary": "cisco-sa-ap-privesc-wEVfp8Ud",
        "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ap-privesc-wEVfp8Ud"
      },
      {
        "category": "external",
        "summary": "Security Vulnerability Policy",
        "url": "https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html"
      }
    ],
    "title": "Cisco Aironet Access Points FlexConnect Multicast DNS Denial of Service Vulnerability",
    "tracking": {
      "current_release_date": "2021-03-24T16:00:00+00:00",
      "generator": {
        "date": "2022-10-22T03:09:54+00:00",
        "engine": {
          "name": "TVCE"
        }
      },
      "id": "cisco-sa-aironet-mdns-dos-E6KwYuMx",
      "initial_release_date": "2021-03-24T16:00:00+00:00",
      "revision_history": [
        {
          "date": "2021-03-12T15:46:28+00:00",
          "number": "1.0.0",
          "summary": "Initial public release."
        }
      ],
      "status": "final",
      "version": "1.0.0"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "category": "product_family",
            "name": "Cisco Aironet Access Point Software (IOS XE Controller)",
            "product": {
              "name": "Cisco Aironet Access Point Software (IOS XE Controller) ",
              "product_id": "CSAFPID-280019"
            }
          }
        ],
        "category": "vendor",
        "name": "Cisco"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2021-1439",
      "ids": [
        {
          "system_name": "Cisco Bug ID",
          "text": "CSCvw63560"
        }
      ],
      "notes": [
        {
          "category": "other",
          "text": "Complete.",
          "title": "Affected Product Comprehensiveness"
        }
      ],
      "product_status": {
        "known_affected": [
          "CSAFPID-280019"
        ]
      },
      "release_date": "2021-03-24T16:00:00+00:00",
      "remediations": [
        {
          "category": "vendor_fix",
          "details": "Cisco has released software updates that address this vulnerability.",
          "product_ids": [
            "CSAFPID-280019"
          ],
          "url": "https://software.cisco.com"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "baseScore": 7.4,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H",
            "version": "3.1"
          },
          "products": [
            "CSAFPID-280019"
          ]
        }
      ],
      "title": "Cisco Aironet Access Points FlexConnect mDNS Denial of Service Vulnerability"
    }
  ]
}