{
  "document": {
    "acknowledgments": [
      {
        "organization": "Siemens",
        "summary": "reporting this vulnerability to CISA"
      }
    ],
    "category": "csaf_security_advisory",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Disclosure is not limited",
      "tlp": {
        "label": "WHITE",
        "url": "https://us-cert.cisa.gov/tlp/"
      }
    },
    "lang": "en-US",
    "notes": [
      {
        "category": "general",
        "text": "This CSAF advisory was extracted from unstructured data and may contain inaccuracies. If you notice any errors, please reach out to the designated contact at CISA CSAF: central@cisa.dhs.gov",
        "title": "CISA Disclaimer"
      },
      {
        "category": "legal_disclaimer",
        "text": "All information products included in https://us-cert.cisa.gov/ics are provided \"as is\" for informational purposes only. The Department of Homeland Security (DHS) does not provide any warranties of any kind regarding any information contained within. DHS does not endorse any commercial product or service, referenced in this product or otherwise. Further dissemination of this product is governed by the Traffic Light Protocol (TLP) marking in the header. For more information about TLP, see https://us-cert.cisa.gov/tlp/.",
        "title": "Legal Notice"
      },
      {
        "category": "summary",
        "text": "Successful exploitation of this vulnerability could allow an unauthenticated remote attacker to create a permanent denial-of-service condition.",
        "title": "Risk evaluation"
      },
      {
        "category": "other",
        "text": "Multiple Sectors",
        "title": "Critical infrastructure sectors"
      },
      {
        "category": "other",
        "text": "Worldwide",
        "title": "Countries/areas deployed"
      },
      {
        "category": "other",
        "text": "Germany",
        "title": "Company headquarters location"
      },
      {
        "category": "general",
        "text": "CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should:",
        "title": "Recommended Practices"
      },
      {
        "category": "general",
        "text": "CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.\nCISA also provides a section for control systems security recommended practices on the ICS webpage onus-cert.cisa.gov. Several recommended practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.",
        "title": "Recommended Practices"
      },
      {
        "category": "general",
        "text": "Additional mitigation guidance and recommended practices are publicly available on the ICS webpage on us-cert.cisa.gov in the Technical Information Paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.\nOrganizations observing any suspected malicious activity should follow their established internal procedures and report their findings to CISA for tracking and correlation against other incidents.",
        "title": "Recommended Practices"
      },
      {
        "category": "general",
        "text": "For further inquiries on security vulnerabilities in Siemens products and solutions, please contact the Siemens ProductCERT: https://www.siemens.com/cert/advisories",
        "title": "Additional Resources"
      },
      {
        "category": "general",
        "text": "Disable OSPF in the layer 3 configuration menu (note that OSPF is disabled by default). The vulnerability is not exploitable, when OSPF is disabled.",
        "title": "Recommended Practices"
      },
      {
        "category": "other",
        "text": "No known public exploits specifically target this vulnerability.",
        "title": "Exploitability"
      }
    ],
    "publisher": {
      "category": "coordinator",
      "contact_details": "Email: CISAservicedesk@cisa.dhs.gov;\n Toll Free: 1-888-282-0870",
      "name": "CISA",
      "namespace": "https://www.cisa.gov/"
    },
    "references": [
      {
        "category": "external",
        "summary": "SSA-116379: Denial-of-Service Vulnerability in OSPF Packet Handling of SCALANCE XM-400 and XR-500 Devices - CSAF Version",
        "url": "https://cert-portal.siemens.com/productcert/csaf/ssa-116379.json"
      },
      {
        "category": "self",
        "summary": "ICS Advisory ICSA-21-131-10 JSON",
        "url": "https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/OT/white/2021/icsa-21-131-10.json"
      },
      {
        "category": "self",
        "summary": "ICS Advisory ICSA-21-131-10 Web Version",
        "url": "https://www.cisa.gov/news-events/ics-advisories/icsa-21-131-10"
      },
      {
        "category": "external",
        "summary": "Recommended Practices",
        "url": "https://us-cert.cisa.gov/ics/alerts/ICS-ALERT-10-301-01"
      },
      {
        "category": "external",
        "summary": "Recommended Practices",
        "url": "https://us-cert.cisa.gov/sites/default/files/recommended_practices/NCCIC_ICS-CERT_Defense_in_Depth_2016_S508C.pdf"
      },
      {
        "category": "external",
        "summary": "Recommended Practices",
        "url": "https://us-cert.cisa.gov/ics/tips/ICS-TIP-12-146-01B"
      },
      {
        "category": "external",
        "summary": "SSA-116379: Denial-of-Service Vulnerability in OSPF Packet Handling of SCALANCE XM-400 and XR-500 Devices - PDF Version",
        "url": "https://cert-portal.siemens.com/productcert/pdf/ssa-116379.pdf"
      },
      {
        "category": "external",
        "summary": "SSA-116379: Denial-of-Service Vulnerability in OSPF Packet Handling of SCALANCE XM-400 and XR-500 Devices - TXT Version",
        "url": "https://cert-portal.siemens.com/productcert/txt/ssa-116379.txt"
      }
    ],
    "title": "Siemens SCALANCE XM-400 and XR-500 Devices",
    "tracking": {
      "current_release_date": "2021-05-11T00:00:00.000000Z",
      "generator": {
        "engine": {
          "name": "CISA CSAF Generator",
          "version": "1.0.0"
        }
      },
      "id": "ICSA-21-131-10",
      "initial_release_date": "2021-05-11T00:00:00.000000Z",
      "revision_history": [
        {
          "date": "2021-05-11T00:00:00.000000Z",
          "legacy_version": "Initial",
          "number": "1",
          "summary": "ICSA-21-131-10 Siemens SCALANCE XM-400 and XR-500 Devices"
        }
      ],
      "status": "final",
      "version": "1"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "\u003c V6.4",
                "product": {
                  "name": "SCALANCE XM-400 Family",
                  "product_id": "CSAFPID-0001"
                }
              }
            ],
            "category": "product_name",
            "name": "SCALANCE XM-400 Family"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "\u003c V6.4",
                "product": {
                  "name": "SCALANCE XR-500 Family",
                  "product_id": "CSAFPID-0002"
                }
              }
            ],
            "category": "product_name",
            "name": "SCALANCE XR-500 Family"
          }
        ],
        "category": "vendor",
        "name": "Siemens"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2020-28393",
      "cwe": {
        "id": "CWE-682",
        "name": "Incorrect Calculation"
      },
      "notes": [
        {
          "category": "summary",
          "text": "The OSPF protocol implementation in affected devices incorrectly handles the number of LSA fields in combination with other modified fields.\n\nAn unauthenticated remote attacker could create a permanent denial-of-service condition by sending specially crafted OSPF packets. Successful exploitation requires OSPF to be enabled on an affected device.",
          "title": "Summary"
        }
      ],
      "product_status": {
        "known_affected": [
          "CSAFPID-0001",
          "CSAFPID-0002"
        ]
      },
      "references": [
        {
          "summary": "CVE-2020-28393 - SCALANCE XM-400 Family",
          "url": "https://support.industry.siemens.com/cs/ww/en/view/109796319/"
        },
        {
          "summary": "CVE-2020-28393 - SCALANCE XR-500 Family",
          "url": "https://support.industry.siemens.com/cs/ww/en/view/109796317/"
        },
        {
          "summary": "CVE-2020-28393 Mitre 5.0 json",
          "url": "https://cert-portal.siemens.com/productcert/mitre/CVE-2020-28393.json"
        },
        {
          "category": "external",
          "summary": "web.nvd.nist.gov",
          "url": "http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2020-28393"
        },
        {
          "category": "external",
          "summary": "www.first.org",
          "url": "https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "details": "Update to V6.4 or later version",
          "product_ids": [
            "CSAFPID-0001"
          ],
          "url": "https://support.industry.siemens.com/cs/ww/en/view/109796319/"
        },
        {
          "category": "vendor_fix",
          "details": "Update to V6.4 or later version",
          "product_ids": [
            "CSAFPID-0002"
          ],
          "url": "https://support.industry.siemens.com/cs/ww/en/view/109796317/"
        },
        {
          "category": "mitigation",
          "details": "Disable OSPF in the layer 3 configuration menu (note that OSPF is disabled by default). The vulnerability is not exploitable, when OSPF is disabled.",
          "product_ids": [
            "CSAFPID-0001",
            "CSAFPID-0002"
          ]
        },
        {
          "category": "mitigation",
          "details": "If OSPF is used, set a password for the OSPF interface and enable MD5 authentication",
          "product_ids": [
            "CSAFPID-0001",
            "CSAFPID-0002"
          ]
        },
        {
          "category": "mitigation",
          "details": "As a general security measure, Siemens strongly recommends to protect network access to devices with appropriate mechanisms. In order to operate the devices in a protected IT environment, Siemens recommends to configure the environment according to Siemens\u0027 operational guidelines for Industrial Security (Download: https://www.siemens.com/cert/operational-guidelines-industrial-security), and to follow the recommendations in the product manuals.\n\nAdditional information on Industrial Security by Siemens can be found at: https://www.siemens.com/industrialsecurity",
          "product_ids": [
            "CSAFPID-0001",
            "CSAFPID-0002"
          ]
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C",
            "version": "3.1"
          },
          "products": [
            "CSAFPID-0001",
            "CSAFPID-0002"
          ]
        }
      ],
      "title": "CVE-2020-28393"
    }
  ]
}