{
  "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 TCP Normalizer of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software operating in transparent mode could allow an unauthenticated, remote attacker to poison MAC address tables, resulting in a denial of service (DoS) vulnerability.\r\n\r\nThis vulnerability is due to incorrect handling of certain TCP segments when the affected device is operating in transparent mode. An attacker could exploit this vulnerability by sending a crafted TCP segment through an affected device. A successful exploit could allow the attacker to poison the MAC address tables in adjacent devices, resulting in network disruption.\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 October 2021 release of the Cisco ASA, FTD, and FMC Security Advisory Bundled publication. For a complete list of the advisories and links to them, see Cisco Event Response: October 2021 Cisco ASA, FMC, and FTD Software Security Advisory Bundled Publication [\"https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-74773\"].",
        "title": "Summary"
      },
      {
        "category": "general",
        "text": "This vulnerability affects Cisco products if they are running a vulnerable release of Cisco ASA Software or FTD Software and have transparent firewall mode configured.\r\n\r\nFor information about which Cisco software releases are vulnerable, see the Fixed Software [\"#fs\"] section of this advisory.\r\n  Determine the Device Configuration\r\nTo determine whether a device is running in transparent mode, log in to the CLI and use the show firewall command. Returned values will be either Router or Transparent. The following example shows the output for a device that is in transparent mode:\r\n\r\n\r\n\u003e show firewall\r\nFirewall mode: Transparent\r\n\u003e\r\n\r\nFor devices running in multi-context mode, use the show firewall command in every context to determine if the device is affected by this vulnerability.",
        "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 Firepower Management Center (FMC) Software.",
        "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\nIn the following table(s), the left column lists Cisco software releases. The center column indicates whether a release is affected by the vulnerability described in this advisory and the first release that includes the fix for this vulnerability. The right column indicates whether a release is affected by any of the Critical or High SIR vulnerabilities described in this bundle and which release includes fixes for those vulnerabilities.\r\n\r\nASA Software\r\n                                Cisco ASA Software Release              First Fixed Release for This Vulnerability              First Fixed Release for All Vulnerabilities Described in the Bundle of Advisories                                              9.7 and earlier1              Migrate to a fixed release.              Migrate to a fixed release.                                  9.8              9.8.4.40              9.8.4.40                                  9.91              Migrate to a fixed release.              Migrate to a fixed release.                                  9.101              Migrate to a fixed release.              Migrate to a fixed release.                                  9.12              9.12.4.24              9.12.4.29                                  9.131              Migrate to a fixed release.              Migrate to a fixed release.                                  9.14              9.14.2.15              9.14.3.9                                  9.15              9.15.1.15              9.15.1.17                                  9.16              Not vulnerable.              9.16.2.3\r\n1. Cisco ASA Software releases 9.7 and earlier as well as releases 9.9, 9.10, and 9.13 have reached end of software maintenance [\"https://www.cisco.com/c/en/us/products/eos-eol-listing.html\"]. Customers are advised to migrate to a supported release that includes the fix for this vulnerability.\r\nFTD Software\r\n                                Cisco FTD Software Release              First Fixed Release for This Vulnerability              First Fixed Release for All Vulnerabilities Described in the Bundle of Advisories                                              6.2.2 and earlier1              Migrate to a fixed release.              Migrate to a fixed release.                                  6.2.3              Migrate to a fixed release.              Migrate to a fixed release.                                  6.3.01              Migrate to a fixed release.              Migrate to a fixed release.                                  6.4.0              6.4.0.13 (Nov 2021)              6.4.0.13 (Nov 2021)                                  6.5.01              Migrate to a fixed release.              Migrate to a fixed release.                                  6.6.0              6.6.5              6.6.5.1                                  6.7.0              6.7.0.2              6.7.0.3 (Jan 2022)                                  7.0.0              Not Vulnerable.              7.0.1\r\n1. Cisco FMC and FTD Software releases 6.2.2 and earlier, as well as releases 6.3.0 and 6.5.0, have reached end of software maintenance [\"https://www.cisco.com/c/en/us/products/eos-eol-listing.html\"]. Customers are advised to migrate to a supported release that includes the fix for this vulnerability.\r\nFor instructions on upgrading your FTD device, see Cisco Firepower Management Center Upgrade Guide [\"https://www.cisco.com/c/en/us/td/docs/security/firepower/upgrade/fpmc-upgrade-guide/getting_started.html\"].\r\n\r\nThe Cisco Product Security Incident Response Team (PSIRT) validates only the affected and fixed release information that is documented in this advisory.",
        "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 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 Adaptive Security Appliance Software and Firepower Threat Defense Software Transparent Mode Denial of Service Vulnerability",
        "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ftd-dos-JxYWMJyL"
      },
      {
        "category": "external",
        "summary": "Cisco Event Response: October 2021 Cisco ASA, FMC, and FTD Software Security Advisory Bundled Publication",
        "url": "https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-74773"
      },
      {
        "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": "end of software maintenance",
        "url": "https://www.cisco.com/c/en/us/products/eos-eol-listing.html"
      },
      {
        "category": "external",
        "summary": "Cisco\u0026nbsp;Firepower Management Center Upgrade Guide",
        "url": "https://www.cisco.com/c/en/us/td/docs/security/firepower/upgrade/fpmc-upgrade-guide/getting_started.html"
      }
    ],
    "title": "Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Transparent Mode Denial of Service Vulnerability",
    "tracking": {
      "current_release_date": "2021-10-27T16:00:00+00:00",
      "generator": {
        "date": "2024-05-10T23:10:33+00:00",
        "engine": {
          "name": "TVCE"
        }
      },
      "id": "cisco-sa-asa-ftd-dos-JxYWMJyL",
      "initial_release_date": "2021-10-27T16:00:00+00:00",
      "revision_history": [
        {
          "date": "2021-10-27T15:39:30+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 Adaptive Security Appliance (ASA) Software",
            "product": {
              "name": "Cisco Adaptive Security Appliance (ASA) Software ",
              "product_id": "CSAFPID-6588"
            }
          },
          {
            "branches": [
              {
                "branches": [
                  {
                    "category": "service_pack",
                    "name": "6.2.3.6",
                    "product": {
                      "name": "6.2.3.6",
                      "product_id": "CSAFPID-248816"
                    }
                  },
                  {
                    "category": "service_pack",
                    "name": "6.2.3.13",
                    "product": {
                      "name": "6.2.3.13",
                      "product_id": "CSAFPID-267675"
                    }
                  }
                ],
                "category": "product_version",
                "name": "6.2"
              },
              {
                "branches": [
                  {
                    "category": "service_pack",
                    "name": "6.6.1",
                    "product": {
                      "name": "6.6.1",
                      "product_id": "CSAFPID-280013"
                    }
                  }
                ],
                "category": "product_version",
                "name": "6.6"
              }
            ],
            "category": "product_family",
            "name": "Cisco Firepower Threat Defense Software"
          },
          {
            "category": "product_name",
            "name": "Cisco 3000 Series Industrial Security Appliances (ISA)",
            "product": {
              "name": "Cisco 3000 Series Industrial Security Appliances (ISA)",
              "product_id": "CSAFPID-277438"
            }
          },
          {
            "category": "product_name",
            "name": "Cisco Firepower 9000 Series",
            "product": {
              "name": "Cisco Firepower 9000 Series",
              "product_id": "CSAFPID-277440"
            }
          },
          {
            "category": "product_name",
            "name": "Cisco Firepower 4100 Series",
            "product": {
              "name": "Cisco Firepower 4100 Series",
              "product_id": "CSAFPID-277441"
            }
          }
        ],
        "category": "vendor",
        "name": "Cisco"
      }
    ],
    "relationships": [
      {
        "category": "installed_on",
        "full_product_name": {
          "name": "Cisco Firepower Threat Defense Software 6.2.3.6 when installed on Cisco Firepower 9000 Series",
          "product_id": "CSAFPID-248816:277440"
        },
        "product_reference": "CSAFPID-248816",
        "relates_to_product_reference": "CSAFPID-277440"
      },
      {
        "category": "installed_on",
        "full_product_name": {
          "name": "Cisco Firepower Threat Defense Software 6.2.3.13 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)",
          "product_id": "CSAFPID-267675:277438"
        },
        "product_reference": "CSAFPID-267675",
        "relates_to_product_reference": "CSAFPID-277438"
      },
      {
        "category": "installed_on",
        "full_product_name": {
          "name": "Cisco Firepower Threat Defense Software 6.6.1 when installed on Cisco Firepower 4100 Series",
          "product_id": "CSAFPID-280013:277441"
        },
        "product_reference": "CSAFPID-280013",
        "relates_to_product_reference": "CSAFPID-277441"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2021-34793",
      "ids": [
        {
          "system_name": "Cisco Bug ID",
          "text": "CSCvx46296"
        }
      ],
      "notes": [
        {
          "category": "other",
          "text": "Complete.",
          "title": "Affected Product Comprehensiveness"
        }
      ],
      "product_status": {
        "known_affected": [
          "CSAFPID-6588",
          "CSAFPID-248816:277440",
          "CSAFPID-267675:277438",
          "CSAFPID-280013:277441"
        ]
      },
      "release_date": "2021-10-27T16:00:00+00:00",
      "remediations": [
        {
          "category": "vendor_fix",
          "details": "Cisco has released software updates that address this vulnerability.",
          "product_ids": [
            "CSAFPID-6588",
            "CSAFPID-248816:277440",
            "CSAFPID-267675:277438",
            "CSAFPID-280013:277441"
          ],
          "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-6588",
            "CSAFPID-248816:277440",
            "CSAFPID-267675:277438",
            "CSAFPID-280013:277441"
          ]
        }
      ],
      "title": "Cisco Adaptive Security Appliance Software and Cisco Firepower Threat Defense Software Transparent Mode Denial of Service Vulnerability"
    }
  ]
}