{
  "document": {
    "acknowledgments": [
      {
        "summary": "Cisco would like to thank Roy Barkay Yosef and Chen Farchi for reporting this vulnerability."
      }
    ],
    "category": "csaf_informational_advisory",
    "csaf_version": "2.0",
    "notes": [
      {
        "category": "summary",
        "text": "On January 18, 2023, Cisco disclosed the following:\r\n\r\nA vulnerability in the URL filtering mechanism of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass the URL reputation filters on an affected device.\r\n\r\nThis vulnerability is due to improper processing of URLs. An attacker could exploit this vulnerability by crafting a URL in a particular way. A successful exploit could allow the attacker to bypass the URL reputation filters that are configured for an affected device, which could allow malicious URLs to pass through the device.\r\nAfter additional investigation, it was determined that this vulnerability is not exploitable. For more information, see the Workarounds [\"#wa\"] section of this advisory.\r\n\r\n",
        "title": "Summary"
      },
      {
        "category": "general",
        "text": "At the time of publication, this vulnerability affected all releases of Cisco AsyncOS Software for Cisco ESA that did not have the Anti-Spam feature enabled.\r\n\r\nSee the Details section in the bug ID(s) at the top of this advisory for the most complete and current information.",
        "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": "Administrators should follow the Best Practice Guide for Anti-Spam, Anti-Virus, Graymail and Outbreak Filters [\"https://www.cisco.com/c/en/us/support/docs/security/email-security-appliance/215164-best-practice-guide-for-anti-spam-anti.html\"] and should ensure that the Cisco Anti-Spam feature is enabled because it contains rules designed to identify specially crafted URLs. It is also recommended that all positive verdicts be either dropped or quarantined.\r\n\r\nWhile this workaround has been deployed and was proven successful in a test environment, customers should determine the applicability and effectiveness in their own environment and under their own use conditions. Customers should be aware that any workaround or mitigation that is implemented may negatively impact the functionality or performance of their network based on intrinsic customer deployment scenarios and limitations. Customers should not deploy any workarounds or mitigations before first evaluating the applicability to their own environment and any impact to such environment.",
        "title": "Workarounds"
      },
      {
        "category": "general",
        "text": "When 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      Fixed Releases\r\nFor information about fixed software releases, see the Details section in the bug ID(s) at the top of this advisory.",
        "title": "Fixed Software"
      },
      {
        "category": "general",
        "text": "To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy [\"http://www.cisco.com/web/about/security/psirt/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": "Cisco would like to thank Roy Barkay Yosef and Chen Farchi for reporting this vulnerability.",
        "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 Email Security Appliance URL Filtering Bypass Vulnerability",
        "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-esa-url-bypass-WbMQqNJh"
      },
      {
        "category": "external",
        "summary": "Cisco Security Vulnerability Policy",
        "url": "https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html"
      },
      {
        "category": "external",
        "summary": "Best Practice Guide for Anti-Spam, Anti-Virus, Graymail and Outbreak Filters",
        "url": "https://www.cisco.com/c/en/us/support/docs/security/email-security-appliance/215164-best-practice-guide-for-anti-spam-anti.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 page",
        "url": "https://www.cisco.com/go/psirt"
      },
      {
        "category": "external",
        "summary": "Security Vulnerability Policy",
        "url": "http://www.cisco.com/web/about/security/psirt/security_vulnerability_policy.html"
      }
    ],
    "title": "Cisco Email Security Appliance URL Filtering Bypass Vulnerability",
    "tracking": {
      "current_release_date": "2023-02-13T15:30:30+00:00",
      "generator": {
        "date": "2023-02-13T15:30:34+00:00",
        "engine": {
          "name": "TVCE"
        }
      },
      "id": "cisco-sa-esa-url-bypass-WbMQqNJh",
      "initial_release_date": "2023-01-18T16:00:00+00:00",
      "revision_history": [
        {
          "date": "2023-01-18T15:55:20+00:00",
          "number": "1.0.0",
          "summary": "Initial public release."
        },
        {
          "date": "2023-02-13T15:30:30+00:00",
          "number": "1.1.0",
          "summary": "Updated the advisory SIR to Informational. Updated the Summary to indicate that the issue is not exploitable. Updated information about vulnerable products. Updated the Workarounds section."
        }
      ],
      "status": "final",
      "version": "1.1.0"
    }
  }
}