icsa-21-103-13
Vulnerability from csaf_cisa
Published
2021-04-13 00:00
Modified
2025-05-06 06:00
Summary
Siemens SIMOTICS CONNECT 400 (Update A)

Notes

Summary
SIMOTICS CONNECT 400 is affected by DNS Client vulnerabilities as initially reported in Siemens Security Advisory SSA-705111 (https://cert-portal.siemens.com/productcert/pdf/ssa-705111.pdf) for the DNS Module in Nucleus RTOS. Siemens has released updates for the SIMOTICS CONNECT 400 and recommends to update to the latest version.
General Recommendations
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. Additional information on Industrial Security by Siemens can be found at: https://www.siemens.com/industrialsecurity
Additional Resources
For further inquiries on security vulnerabilities in Siemens products and solutions, please contact the Siemens ProductCERT: https://www.siemens.com/cert/advisories
Terms of Use
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.
Legal Notice
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/.
Advisory Conversion Disclaimer
This CISA CSAF advisory was converted from Siemens ProductCERT's CSAF advisory.
Critical infrastructure sectors
Multiple
Countries/areas deployed
Worldwide
Company headquarters location
Germany
Recommended Practices
CISA recommends users take defensive measures to minimize the exploitation risk of this vulnerability.
Recommended Practices
Minimize network exposure for all control system devices and/or systems, and ensure they are not accessible from the internet.
Recommended Practices
Locate control system networks and remote devices behind firewalls and isolate them from business networks.
Recommended Practices
When remote access is required, use more secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most recent version available. Also recognize VPN is only as secure as its connected devices.
Recommended Practices
CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.
Recommended Practices
CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.
Recommended Practices
CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets. Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.
Recommended Practices
Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents.


To clipboard 

{
  "document": {
    "acknowledgments": [
      {
        "organization": "Siemens ProductCERT",
        "summary": "reporting this vulnerability to CISA."
      },
      {
        "names": [
          "Daniel dos Santos"
        ],
        "organization": "Forescout Technologies Inc.",
        "summary": "coordinated disclosure"
      }
    ],
    "category": "csaf_security_advisory",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Disclosure is not limited",
      "tlp": {
        "label": "WHITE",
        "url": "https://us-cert.cisa.gov/tlp/"
      }
    },
    "notes": [
      {
        "category": "summary",
        "text": "SIMOTICS CONNECT 400 is affected by DNS Client vulnerabilities as initially reported in Siemens Security Advisory SSA-705111 (https://cert-portal.siemens.com/productcert/pdf/ssa-705111.pdf) for the DNS Module in Nucleus RTOS.\n\nSiemens has released updates for the SIMOTICS CONNECT 400 and recommends to update to the latest version.",
        "title": "Summary"
      },
      {
        "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\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",
        "title": "General Recommendations"
      },
      {
        "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": "legal_disclaimer",
        "text": "Siemens Security Advisories are subject to the terms and conditions contained in Siemens\u0027 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\u0027 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.",
        "title": "Terms of Use"
      },
      {
        "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": "other",
        "text": "This CISA CSAF advisory was converted from Siemens ProductCERT\u0027s CSAF advisory.",
        "title": "Advisory Conversion Disclaimer"
      },
      {
        "category": "other",
        "text": "Multiple",
        "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 exploitation risk of this vulnerability.",
        "title": "Recommended Practices"
      },
      {
        "category": "general",
        "text": "Minimize network exposure for all control system devices and/or systems, and ensure they are not accessible from the internet.",
        "title": "Recommended Practices"
      },
      {
        "category": "general",
        "text": "Locate control system networks and remote devices behind firewalls and isolate them from business networks.",
        "title": "Recommended Practices"
      },
      {
        "category": "general",
        "text": "When remote access is required, use more secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most recent version available. Also recognize VPN is only as secure as its connected devices.",
        "title": "Recommended Practices"
      },
      {
        "category": "general",
        "text": "CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.",
        "title": "Recommended Practices"
      },
      {
        "category": "general",
        "text": "CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.",
        "title": "Recommended Practices"
      },
      {
        "category": "general",
        "text": "CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets. Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.",
        "title": "Recommended Practices"
      },
      {
        "category": "general",
        "text": "Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents.",
        "title": "Recommended Practices"
      }
    ],
    "publisher": {
      "category": "other",
      "contact_details": "central@cisa.dhs.gov",
      "name": "CISA",
      "namespace": "https://www.cisa.gov/"
    },
    "references": [
      {
        "category": "self",
        "summary": "SSA-669158: DNS Client Vulnerabilities in SIMOTICS CONNECT 400 - CSAF Version",
        "url": "https://cert-portal.siemens.com/productcert/csaf/ssa-669158.json"
      },
      {
        "category": "self",
        "summary": "SSA-669158: DNS Client Vulnerabilities in SIMOTICS CONNECT 400 - TXT Version",
        "url": "https://cert-portal.siemens.com/productcert/txt/ssa-669158.txt"
      },
      {
        "category": "self",
        "summary": "SSA-669158: DNS Client Vulnerabilities in SIMOTICS CONNECT 400 - PDF Version",
        "url": "https://cert-portal.siemens.com/productcert/pdf/ssa-669158.pdf"
      },
      {
        "category": "self",
        "summary": "ICS Advisory ICSA-21-103-13 JSON",
        "url": "https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/OT/white/2021/icsa-21-103-13.json"
      },
      {
        "category": "self",
        "summary": "ICS Advisory ICSA-21-103-13 - Web Version",
        "url": "https://www.cisa.gov/news-events/ics-advisories/icsa-21-103-13"
      },
      {
        "category": "external",
        "summary": "Recommended Practices",
        "url": "https://www.cisa.gov/uscert/ics/alerts/ICS-ALERT-10-301-01"
      },
      {
        "category": "external",
        "summary": "Recommended Practices",
        "url": "https://www.cisa.gov/resources-tools/resources/ics-recommended-practices"
      },
      {
        "category": "external",
        "summary": "Recommended Practices",
        "url": "https://www.cisa.gov/topics/industrial-control-systems"
      },
      {
        "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://www.cisa.gov/sites/default/files/publications/Cybersecurity_Best_Practices_for_Industrial_Control_Systems.pdf"
      },
      {
        "category": "external",
        "summary": "Recommended Practices",
        "url": "https://www.cisa.gov/uscert/ics/tips/ICS-TIP-12-146-01B"
      }
    ],
    "title": "Siemens SIMOTICS CONNECT 400 (Update A)",
    "tracking": {
      "current_release_date": "2025-05-06T06:00:00.000000Z",
      "generator": {
        "engine": {
          "name": "CISA CSAF Generator",
          "version": "1.0.0"
        }
      },
      "id": "ICSA-21-103-13",
      "initial_release_date": "2021-04-13T00:00:00.000000Z",
      "revision_history": [
        {
          "date": "2021-04-13T00:00:00.000000Z",
          "legacy_version": "1.0",
          "number": "1",
          "summary": "Publication Date"
        },
        {
          "date": "2022-03-08T00:00:00.000000Z",
          "legacy_version": "1.1",
          "number": "2",
          "summary": "Added solution for CVE-2021-25677"
        },
        {
          "date": "2025-05-06T06:00:00.000000Z",
          "legacy_version": "Revision",
          "number": "3",
          "summary": "Revision - Fixing typos"
        }
      ],
      "status": "final",
      "version": "3"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "\u003cV0.5.0.0",
                "product": {
                  "name": "SIMOTICS CONNECT 400",
                  "product_id": "CSAFPID-0001"
                }
              }
            ],
            "category": "product_name",
            "name": "SIMOTICS CONNECT 400"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "\u003e=V0.5.0.0_\u003cV1.0.0.0",
                "product": {
                  "name": "SIMOTICS CONNECT 400",
                  "product_id": "CSAFPID-0002"
                }
              }
            ],
            "category": "product_name",
            "name": "SIMOTICS CONNECT 400"
          }
        ],
        "category": "vendor",
        "name": "Siemens"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2020-27736",
      "cwe": {
        "id": "CWE-170",
        "name": "Improper Null Termination"
      },
      "notes": [
        {
          "category": "summary",
          "text": "The DNS domain name label parsing functionality does not properly validate the null-terminated name in DNS-responses. The parsing of malformed responses could result in a read past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to cause a denial-of-service condition or leak the read memory.",
          "title": "Summary"
        }
      ],
      "product_status": {
        "known_affected": [
          "CSAFPID-0001"
        ]
      },
      "references": [
        {
          "summary": "CVE-2020-27736 - SIMOTICS CONNECT 400",
          "url": "https://support.industry.siemens.com/cs/ww/en/view/109778383/"
        },
        {
          "summary": "CVE-2020-27736 Mitre 5.0 json",
          "url": "https://cert-portal.siemens.com/productcert/mitre/CVE-2020-27736.json"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "details": "Update to V0.5.0.0 or later version",
          "product_ids": [
            "CSAFPID-0001"
          ],
          "url": "https://support.industry.siemens.com/cs/ww/en/view/109778383/"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "baseScore": 6.5,
            "baseSeverity": "MEDIUM",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H/E:P/RL:O/RC:C",
            "version": "3.1"
          },
          "products": [
            "CSAFPID-0001"
          ]
        }
      ],
      "title": "CVE-2020-27736"
    },
    {
      "cve": "CVE-2020-27737",
      "cwe": {
        "id": "CWE-125",
        "name": "Out-of-bounds Read"
      },
      "notes": [
        {
          "category": "summary",
          "text": "The DNS response parsing functionality does not properly validate various length and counts of the records. The parsing of malformed responses could result in a read past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to cause a denial-of-service condition or leak the memory past the allocated structure.",
          "title": "Summary"
        }
      ],
      "product_status": {
        "known_affected": [
          "CSAFPID-0001"
        ]
      },
      "references": [
        {
          "summary": "CVE-2020-27737 - SIMOTICS CONNECT 400",
          "url": "https://support.industry.siemens.com/cs/ww/en/view/109778383/"
        },
        {
          "summary": "CVE-2020-27737 Mitre 5.0 json",
          "url": "https://cert-portal.siemens.com/productcert/mitre/CVE-2020-27737.json"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "details": "Update to V0.5.0.0 or later version",
          "product_ids": [
            "CSAFPID-0001"
          ],
          "url": "https://support.industry.siemens.com/cs/ww/en/view/109778383/"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "baseScore": 6.5,
            "baseSeverity": "MEDIUM",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H/E:P/RL:O/RC:C",
            "version": "3.1"
          },
          "products": [
            "CSAFPID-0001"
          ]
        }
      ],
      "title": "CVE-2020-27737"
    },
    {
      "cve": "CVE-2020-27738",
      "cwe": {
        "id": "CWE-788",
        "name": "Access of Memory Location After End of Buffer"
      },
      "notes": [
        {
          "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 read access past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to cause a denial-of-service condition.",
          "title": "Summary"
        }
      ],
      "product_status": {
        "known_affected": [
          "CSAFPID-0001"
        ]
      },
      "references": [
        {
          "summary": "CVE-2020-27738 - SIMOTICS CONNECT 400",
          "url": "https://support.industry.siemens.com/cs/ww/en/view/109778383/"
        },
        {
          "summary": "CVE-2020-27738 Mitre 5.0 json",
          "url": "https://cert-portal.siemens.com/productcert/mitre/CVE-2020-27738.json"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "details": "Update to V0.5.0.0 or later version",
          "product_ids": [
            "CSAFPID-0001"
          ],
          "url": "https://support.industry.siemens.com/cs/ww/en/view/109778383/"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "baseScore": 6.5,
            "baseSeverity": "MEDIUM",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H/E:P/RL:O/RC:C",
            "version": "3.1"
          },
          "products": [
            "CSAFPID-0001"
          ]
        }
      ],
      "title": "CVE-2020-27738"
    },
    {
      "cve": "CVE-2021-25677",
      "cwe": {
        "id": "CWE-330",
        "name": "Use of Insufficiently Random Values"
      },
      "notes": [
        {
          "category": "summary",
          "text": "The DNS client does not properly randomize DNS transaction IDs. That could allow an attacker to poison the DNS cache or spoof DNS resolving.",
          "title": "Summary"
        }
      ],
      "product_status": {
        "known_affected": [
          "CSAFPID-0001",
          "CSAFPID-0002"
        ]
      },
      "references": [
        {
          "summary": "CVE-2021-25677 - SIMOTICS CONNECT 400",
          "url": "https://support.industry.siemens.com/cs/ww/en/view/109778383/"
        },
        {
          "summary": "CVE-2021-25677 - SIMOTICS CONNECT 400",
          "url": "https://support.industry.siemens.com/cs/ww/en/view/109778383/"
        },
        {
          "summary": "CVE-2021-25677 Mitre 5.0 json",
          "url": "https://cert-portal.siemens.com/productcert/mitre/CVE-2021-25677.json"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "details": "Update to V0.5.0.0 or later version",
          "product_ids": [
            "CSAFPID-0001"
          ],
          "url": "https://support.industry.siemens.com/cs/ww/en/view/109778383/"
        },
        {
          "category": "vendor_fix",
          "details": "Update to V1.0.0.0 or later version",
          "product_ids": [
            "CSAFPID-0002"
          ],
          "url": "https://support.industry.siemens.com/cs/ww/en/view/109778383/"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:P/RL:O/RC:C",
            "version": "3.1"
          },
          "products": [
            "CSAFPID-0001",
            "CSAFPID-0002"
          ]
        }
      ],
      "title": "CVE-2021-25677"
    }
  ]
}


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