{
  "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 with the access control list (ACL) management within a stacked switch configuration of Cisco Business 250 Series Smart Switches and Business 350 Series Managed Switches could allow an unauthenticated, remote attacker to bypass protection offered by a configured ACL on an affected device.\r\n\r\nThis vulnerability is due to incorrect processing of ACLs on a stacked configuration when either the primary or backup switches experience a full stack reload or power cycle. An attacker could exploit this vulnerability by sending crafted traffic through an affected device. A successful exploit could allow the attacker to bypass configured ACLs, causing traffic to be dropped or forwarded in an unexpected manner. The attacker does not have control over the conditions that result in the device being in the vulnerable state.\r\n\r\nNote: In the vulnerable state, the ACL would be correctly applied on the primary devices but could be incorrectly applied to the backup devices.\r\n\r\nCisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.\r\n\r\n",
        "title": "Summary"
      },
      {
        "category": "general",
        "text": "At the time of publication, this vulnerability affected the following Cisco products if they were running a vulnerable release of Cisco Small Business Firmware Software and were in a stacked configuration with ACLs configured:\r\n\r\n250 Series Smart Switches\r\n350 Series Managed Switches\r\n350X Series Stackable Managed Switches\r\n550X Series Stackable Managed Switches\r\nBusiness 250 Series Smart Switches\r\nBusiness 350 Series Managed Switches\r\n\r\nFor information on the stackable configuration of Business Switches, see the Stacking Guidelines for Cisco Business Switches [\"https://www.cisco.com/c/en/us/support/docs/smb/switches/Cisco-Business-Switching/kmgmt2836-Stacking-Guidelines-for-CBS.html\"].\r\n\r\nFor information about which Cisco software releases were vulnerable at the time of publication, see the Fixed Software [\"#fs\"] section of this advisory. See 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": "There are no workarounds that address this vulnerability.\r\n\r\nThis vulnerability can leave the ACL configuration in an undefined state on the switch. As a mitigation, unbind the ACL from the non-working VLANs and then bind the ACL again. This is not a permanent mitigation. It would need to be reapplied if any switch stack member reloads or is power cycled.\r\n\r\nFor the specific steps for unbinding and rebinding non-working ACLs, see the Cisco Business Switches 350 Series CLI Guide [\"https://www.cisco.com/c/en/us/td/docs/switches/lan/csbms/CBS_250_350/CLI/cbs-350-cli-.pdf\"] (pages 105 to 107) and the Cisco Business 350 Series Switches Administration Guide [\"https://www.cisco.com/c/en/us/td/docs/switches/lan/csbms/CBS_250_350/Administration-Guide/cbs-350.pdf\"] (pages 325 to 326). Contact the Cisco Technical Assistance Center (TAC) if further guidance is needed.\r\n\r\nWhile this mitigation 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\nAt the time of publication, the release information in the following tables was accurate. See the Details section in the bug ID(s) at the top of this advisory for the most complete and current information.\r\n\r\nBusiness 250 Series Smart Switches and Business 350 Series Managed Switches\r\n        Cisco Firmware Release  First Fixed Release          3.4 and earlier  3.4.0.17\r\n250 Series Smart Switches, 350 Series Managed Switches, 350X Series Stackable Managed Switches, and 550X Series Stackable Managed Switches\r\n        Cisco Firmware Release  First Fixed Release          2.5 and earlier  2.5.9.54\r\nTo download the firmware from the Software Center [\"https://software.cisco.com/download/home\"] on Cisco.com, click Browse all and choose Switches \u003e LAN Switches - Small Business.\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 [\"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 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 Small Business Series Switches Stacked Reload ACL Bypass Vulnerability",
        "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sb-bus-acl-bypass-5zn9hNJk"
      },
      {
        "category": "external",
        "summary": "Cisco Security Vulnerability Policy",
        "url": "https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html"
      },
      {
        "category": "external",
        "summary": "Stacking Guidelines for Cisco Business Switches",
        "url": "https://www.cisco.com/c/en/us/support/docs/smb/switches/Cisco-Business-Switching/kmgmt2836-Stacking-Guidelines-for-CBS.html"
      },
      {
        "category": "external",
        "summary": "Cisco Business Switches 350 Series CLI Guide",
        "url": "https://www.cisco.com/c/en/us/td/docs/switches/lan/csbms/CBS_250_350/CLI/cbs-350-cli-.pdf"
      },
      {
        "category": "external",
        "summary": "Cisco Business 350 Series Switches Administration Guide",
        "url": "https://www.cisco.com/c/en/us/td/docs/switches/lan/csbms/CBS_250_350/Administration-Guide/cbs-350.pdf"
      },
      {
        "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": "Software Center",
        "url": "https://software.cisco.com/download/home"
      },
      {
        "category": "external",
        "summary": "Security Vulnerability Policy",
        "url": "http://www.cisco.com/web/about/security/psirt/security_vulnerability_policy.html"
      }
    ],
    "title": "Cisco Small Business Series Switches Stacked Reload ACL Bypass Vulnerability",
    "tracking": {
      "current_release_date": "2024-01-24T16:00:00+00:00",
      "generator": {
        "date": "2024-01-24T15:52:28+00:00",
        "engine": {
          "name": "TVCE"
        }
      },
      "id": "cisco-sa-sb-bus-acl-bypass-5zn9hNJk",
      "initial_release_date": "2024-01-24T16:00:00+00:00",
      "revision_history": [
        {
          "date": "2024-01-24T15:52:23+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 Small Business Smart and Managed Switches",
            "product": {
              "name": "Cisco Small Business Smart and Managed Switches ",
              "product_id": "CSAFPID-278027"
            }
          }
        ],
        "category": "vendor",
        "name": "Cisco"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2024-20263",
      "ids": [
        {
          "system_name": "Cisco Bug ID",
          "text": "CSCwf48882"
        },
        {
          "system_name": "Cisco Bug ID",
          "text": "CSCwh68993"
        }
      ],
      "notes": [
        {
          "category": "other",
          "text": "Complete.",
          "title": "Affected Product Comprehensiveness"
        }
      ],
      "product_status": {
        "known_affected": [
          "CSAFPID-278027"
        ]
      },
      "release_date": "2024-01-24T16:00:00+00:00",
      "remediations": [
        {
          "category": "vendor_fix",
          "details": "Cisco has released software updates that address this vulnerability.",
          "product_ids": [
            "CSAFPID-278027"
          ],
          "url": "https://software.cisco.com"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "baseScore": 5.8,
            "baseSeverity": "MEDIUM",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N",
            "version": "3.1"
          },
          "products": [
            "CSAFPID-278027"
          ]
        }
      ],
      "title": "Cisco Small Business Series Switches Stacked Reload ACL Bypass Vulnerability"
    }
  ]
}