{
  "document": {
    "title": "SSA-185699: Out of Bounds Write Vulnerabilities (NAME:WRECK) in the DNS Module of Nucleus RTOS",
    "category": "Siemens Security Advisory",
    "csaf_version": "2.0",
    "publisher": {
      "name": "Siemens ProductCERT",
      "contact_details": "productcert@siemens.com",
      "category": "vendor",
      "namespace": "https://www.siemens.com"
    },
    "distribution": {
      "text": "Disclosure is not limited.",
      "tlp": {
        "label": "WHITE"
      }
    },
    "tracking": {
      "id": "SSA-185699",
      "status": "final",
      "version": "3",
      "revision_history": [
        {
          "number": "1",
          "legacy_version": "1.0",
          "date": "2021-04-13T00:00:00Z",
          "summary": "Publication Date"
        },
        {
          "number": "2",
          "legacy_version": "1.1",
          "date": "2021-11-09T00:00:00Z",
          "summary": "Consolidated list of products"
        },
        {
          "number": "3",
          "legacy_version": "1.2",
          "date": "2022-01-11T00:00:00Z",
          "summary": "Removed CAPITAL VSTAR as not affected"
        }
      ],
      "initial_release_date": "2021-04-13T00:00:00Z",
      "current_release_date": "2022-01-11T00:00:00Z",
      "generator": {
        "engine": {
          "name": "Siemens ProductCERT CSAF Generator",
          "version": "1"
        }
      }
    },
    "notes": [
      {
        "title": "Summary",
        "category": "summary",
        "text": "Security researchers discovered and disclosed 9 vulnerabilities in several DNS implementations, also known as “NAME:WRECK” vulnerabilities. The vulnerabilities described in this advisory are from this set.\n\nThe DNS client of the networking component (Nucleus NET) in Nucleus Real-Time Operating System (RTOS) contains two out of bounds write vulnerabilities in the handling of DNS responses that could allow an attacker to cause a denial-of-service condition or to remotely execute code.\n\nSiemens has released updates for several affected products and recommends to update to the latest versions. Siemens recommends specific countermeasures for products where updates are not available."
      },
      {
        "title": "General Recommendations",
        "category": "general",
        "text": "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' 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"
      },
      {
        "title": "Additional Resources",
        "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": "Terms of Use",
        "category": "legal_disclaimer",
        "text": "Siemens Security Advisories are subject to the terms and conditions contained in Siemens' underlying license terms or other applicable agreements previously agreed to with Siemens (hereinafter \"License Terms\"). To the extent applicable to information, software or documentation made available in or through a Siemens Security Advisory, the Terms of Use of Siemens' Global Website (https://www.siemens.com/terms_of_use, hereinafter \"Terms of Use\"), in particular Sections 8-10 of the Terms of Use, shall apply additionally. In case of conflicts, the License Terms shall prevail over the Terms of Use."
      }
    ],
    "references": [
      {
        "category": "self",
        "url": "https://cert-portal.siemens.com/productcert/pdf/ssa-185699.pdf",
        "summary": "SSA-185699: Out of Bounds Write Vulnerabilities (NAME:WRECK) in the DNS Module of Nucleus RTOS - PDF Version"
      },
      {
        "category": "self",
        "url": "https://cert-portal.siemens.com/productcert/txt/ssa-185699.txt",
        "summary": "SSA-185699: Out of Bounds Write Vulnerabilities (NAME:WRECK) in the DNS Module of Nucleus RTOS - TXT Version"
      },
      {
        "category": "self",
        "url": "https://cert-portal.siemens.com/productcert/csaf/ssa-185699.json",
        "summary": "SSA-185699: Out of Bounds Write Vulnerabilities (NAME:WRECK) in the DNS Module of Nucleus RTOS - CSAF Version"
      }
    ],
    "acknowledgments": [
      {
        "names": [
          "Daniel dos Santos"
        ],
        "organization": "Forescout Technologies Inc.",
        "summary": "coordinated disclosure"
      }
    ]
  },
  "product_tree": {
    "branches": [
      {
        "name": "Siemens",
        "category": "vendor",
        "branches": [
          {
            "name": "Nucleus NET",
            "category": "product_name",
            "branches": [
              {
                "name": "< V5.2",
                "category": "product_version_range",
                "product": {
                  "product_id": "1",
                  "name": "Nucleus NET"
                }
              }
            ]
          },
          {
            "name": "Nucleus Source Code",
            "category": "product_name",
            "branches": [
              {
                "name": "Versions including affected DNS modules",
                "category": "product_version_range",
                "product": {
                  "product_id": "2",
                  "name": "Nucleus Source Code"
                }
              }
            ]
          }
        ]
      }
    ]
  },
  "vulnerabilities": [
    {
      "title": "CVE-2020-15795",
      "notes": [
        {
          "title": "Summary",
          "category": "summary",
          "text": "The DNS domain name label parsing functionality does not properly validate the names in DNS-responses. The parsing of malformed responses could result in a write past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to execute code in the context of the current process or cause a denial-of-service condition."
        }
      ],
      "cve": "CVE-2020-15795",
      "cwe": {
        "id": "CWE-787",
        "name": "Out-of-bounds Write"
      },
      "product_status": {
        "known_affected": [
          "1",
          "2"
        ]
      },
      "scores": [
        {
          "cvss_v3": {
            "version": "3.1",
            "baseScore": 8.1,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C"
          },
          "products": [
            "1",
            "2"
          ]
        }
      ],
      "remediations": [
        {
          "product_ids": [
            "1"
          ],
          "category": "mitigation",
          "details": "Update to the latest version of Nucleus ReadyStart V3 or V4"
        },
        {
          "product_ids": [
            "1"
          ],
          "category": "mitigation",
          "details": "Note that the latest version of Nucleus NET (V5.2) is not affected, but is already beyond end of software support"
        },
        {
          "product_ids": [
            "1"
          ],
          "category": "mitigation",
          "details": "Contact customer support or your local Nucleus Sales team for mitigation advice"
        },
        {
          "product_ids": [
            "1"
          ],
          "category": "no_fix_planned",
          "details": "Currently no remediation is planned"
        },
        {
          "product_ids": [
            "2"
          ],
          "category": "vendor_fix",
          "details": "Contact customer support to receive patch and update information"
        },
        {
          "product_ids": [
            "1",
            "2"
          ],
          "category": "workaround",
          "details": "Avoid using DNS client of affected versions"
        }
      ],
      "references": [
        {
          "url": "https://cert-portal.siemens.com/productcert/mitre/CVE-2020-15795.json",
          "summary": "CVE-2020-15795 Mitre 5.0 json"
        }
      ]
    },
    {
      "title": "CVE-2020-27009",
      "notes": [
        {
          "title": "Summary",
          "category": "summary",
          "text": "The DNS domain name record decompression functionality does not properly validate the pointer offset values. The parsing of malformed responses could result in a write past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to execute code in the context of the current process or cause a denial-of-service condition."
        }
      ],
      "cve": "CVE-2020-27009",
      "cwe": {
        "id": "CWE-823",
        "name": "Use of Out-of-range Pointer Offset"
      },
      "product_status": {
        "known_affected": [
          "1",
          "2"
        ]
      },
      "scores": [
        {
          "cvss_v3": {
            "version": "3.1",
            "baseScore": 8.1,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C"
          },
          "products": [
            "1",
            "2"
          ]
        }
      ],
      "remediations": [
        {
          "product_ids": [
            "1"
          ],
          "category": "mitigation",
          "details": "Update to the latest version of Nucleus ReadyStart V3 or V4"
        },
        {
          "product_ids": [
            "1"
          ],
          "category": "mitigation",
          "details": "Note that the latest version of Nucleus NET (V5.2) is not affected, but is already beyond end of software support"
        },
        {
          "product_ids": [
            "1"
          ],
          "category": "mitigation",
          "details": "Contact customer support or your local Nucleus Sales team for mitigation advice"
        },
        {
          "product_ids": [
            "1"
          ],
          "category": "no_fix_planned",
          "details": "Currently no remediation is planned"
        },
        {
          "product_ids": [
            "2"
          ],
          "category": "vendor_fix",
          "details": "Contact customer support to receive patch and update information"
        },
        {
          "product_ids": [
            "1",
            "2"
          ],
          "category": "workaround",
          "details": "Avoid using DNS client of affected versions"
        }
      ],
      "references": [
        {
          "url": "https://cert-portal.siemens.com/productcert/mitre/CVE-2020-27009.json",
          "summary": "CVE-2020-27009 Mitre 5.0 json"
        }
      ]
    }
  ]
}