{
  "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 HTTPS decryption feature of Cisco Web Security Appliance (WSA) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition.\r\n\r\nThe vulnerability is due to insufficient validation of Secure Sockets Layer (SSL) server certificates. An attacker could exploit this vulnerability by installing a malformed certificate in a web server and sending a request to it through the Cisco WSA. A successful exploit could allow the attacker to cause an unexpected restart of the proxy process on an affected device.\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-20190703-wsa-dos [\"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190703-wsa-dos\"]",
        "title": "Summary"
      },
      {
        "category": "general",
        "text": "This vulnerability affects Cisco AsyncOS Software for Cisco WSA, both virtual and hardware appliances, when the devices have the HTTPS Proxy feature enabled and have at least one decryption policy configured. The HTTPS Proxy feature is disabled by default.\r\n\r\nFor information about which Cisco AsyncOS Software releases are vulnerable, see the Fixed Software [\"#fs\"] section of this advisory.\r\n\r\nTo determine whether the HTTPS Proxy feature is enabled for a WSA, administrators can log in to the web interface of the WSA and navigate to Security Services \u003e HTTPS Proxy. The value in the HTTPS Proxy field indicates whether the feature is enabled or disabled.",
        "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.",
        "title": "Products Confirmed Not Vulnerable"
      },
      {
        "category": "general",
        "text": "Exploitation of this vulnerability will cause the proxy process to generate a core file with a particular backtrace. Contact the Cisco Technical Assistance Center (TAC) to review the core file and determine whether the device has been compromised by exploitation of this vulnerability and to identify the IP address of the server that is hosting the malformed certificate.",
        "title": "Indicators of Compromise"
      },
      {
        "category": "general",
        "text": "There are no workarounds that address this vulnerability. It is possible to mitigate the impact of this vulnerability by bypassing decryption for web servers that are hosting malformed certificates that exploit this vulnerability. For details about how to configure the bypass, refer to  AsyncOS User Guide [\"https://www.cisco.com/c/en/us/td/docs/security/wsa/wsa11-7/user_guide/b_WSA_UserGuide_11_7/b_WSA_UserGuide_11_7_appendix_010111.html#task_1316480\"].",
        "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, 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 TAC or their contracted maintenance providers.\r\n\r\nCustomers Without Service Contracts\r\n\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\r\nFixed Releases\r\n\r\nCustomers are advised to upgrade to an appropriate fixed software release as indicated in the following table:\r\n                                Cisco AsyncOS Software Major Release              First Fixed Release                                              Prior to 10.5              Migrate to 10.5.5-005                                  10.5              10.5.5-005                                  11.5              11.5.2-020                                  11.7              Not vulnerable\r\nIn most cases, the software can be upgraded over the network by using the System Upgrade options in the Cisco WSA web interface. To upgrade a device by using the web interface:\r\n\r\nChoose System Administration \u003e System Upgrade.\r\nClick Upgrade Options.\r\nChoose Download and Install.\r\nChoose the release to upgrade to.\r\nIn the Upgrade Preparation area, choose the appropriate options.\r\nClick Proceed to begin the upgrade. A progress bar displays the status of the upgrade.\r\n\r\nAfter the upgrade is complete, the device reboots.",
        "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 Web Security Appliance HTTPS Certificate Denial of Service Vulnerability",
        "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190703-wsa-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-20190703-wsa-dos",
        "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190703-wsa-dos"
      },
      {
        "category": "external",
        "summary": "AsyncOS User Guide",
        "url": "https://www.cisco.com/c/en/us/td/docs/security/wsa/wsa11-7/user_guide/b_WSA_UserGuide_11_7/b_WSA_UserGuide_11_7_appendix_010111.html#task_1316480"
      },
      {
        "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": "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": "Security Vulnerability Policy",
        "url": "https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html"
      }
    ],
    "title": "Cisco Web Security Appliance HTTPS Certificate Denial of Service Vulnerability",
    "tracking": {
      "current_release_date": "2019-07-03T16:00:00+00:00",
      "generator": {
        "date": "2022-09-03T03:13:48+00:00",
        "engine": {
          "name": "TVCE"
        }
      },
      "id": "cisco-sa-20190703-wsa-dos",
      "initial_release_date": "2019-07-03T16:00:00+00:00",
      "revision_history": [
        {
          "date": "2019-07-03T14:33:05+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 Web Security Appliance (WSA)",
            "product": {
              "name": "Cisco Web Security Appliance (WSA) ",
              "product_id": "CSAFPID-189789"
            }
          }
        ],
        "category": "vendor",
        "name": "Cisco"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2019-1886",
      "ids": [
        {
          "system_name": "Cisco Bug ID",
          "text": "CSCvo33747"
        }
      ],
      "notes": [
        {
          "category": "other",
          "text": "Complete.",
          "title": "Affected Product Comprehensiveness"
        }
      ],
      "product_status": {
        "known_affected": [
          "CSAFPID-189789"
        ]
      },
      "release_date": "2019-07-03T16:00:00+00:00",
      "remediations": [
        {
          "category": "vendor_fix",
          "details": "Cisco has released software updates that address this vulnerability.",
          "product_ids": [
            "CSAFPID-189789"
          ],
          "url": "https://software.cisco.com"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "baseScore": 8.6,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H",
            "version": "3.0"
          },
          "products": [
            "CSAFPID-189789"
          ]
        }
      ],
      "title": "Cisco Web Security Appliance HTTPS Certificate Denial of Service Vulnerability"
    }
  ]
}