{
  "document": {
    "acknowledgments": [
      {
        "organization": "Siemens ProductCERT",
        "summary": "reporting this vulnerability to CISA."
      },
      {
        "names": [
          "Paul Noalhyt",
          "David Doggett"
        ],
        "organization": "Red Balloon Security",
        "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": "A buffer overflow vulnerability in the integrated web server of multiple APOGEE and TALON automation devices could allow a remote attacker to execute arbitrary code on the devices with root privileges.\n\nAffected devices include the APOGEE MBC/MEC/PXC P2 Ethernet devices with Power Open Processors (PPC), APOGEE PXC BACnet devices, and TALON TC BACnet devices.\n\nSiemens has released updates for several affected products and recommends to update to the latest versions. Siemens recommends countermeasures for products where updates are not, or not yet available.",
        "title": "Summary"
      },
      {
        "category": "general",
        "text": "As a general security measure Siemens strongly recommends to protect network access to affected products with appropriate mechanisms. It is advised to follow recommended security practices in order to run the devices in a protected IT environment.",
        "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 these vulnerabilities.",
        "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-944498: Buffer Overflow Vulnerability in Web Server of APOGEE and TALON Automation Devices - CSAF Version",
        "url": "https://cert-portal.siemens.com/productcert/csaf/ssa-944498.json"
      },
      {
        "category": "self",
        "summary": "SSA-944498: Buffer Overflow Vulnerability in Web Server of APOGEE and TALON Automation Devices - TXT Version",
        "url": "https://cert-portal.siemens.com/productcert/txt/ssa-944498.txt"
      },
      {
        "category": "self",
        "summary": "SSA-944498: Buffer Overflow Vulnerability in Web Server of APOGEE and TALON Automation Devices - PDF Version",
        "url": "https://cert-portal.siemens.com/productcert/pdf/ssa-944498.pdf"
      },
      {
        "category": "self",
        "summary": "ICS Advisory ICSA-21-257-07 JSON",
        "url": "https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/OT/white/2021/icsa-21-257-07.json"
      },
      {
        "category": "self",
        "summary": "ICS Advisory ICSA-21-257-07 - Web Version",
        "url": "https://www.cisa.gov/news-events/ics-advisories/icsa-21-257-07"
      },
      {
        "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 APOGEE and TALON",
    "tracking": {
      "current_release_date": "2025-05-06T06:00:00.000000Z",
      "generator": {
        "engine": {
          "name": "CISA CSAF Generator",
          "version": "1.0.0"
        }
      },
      "id": "ICSA-21-257-07",
      "initial_release_date": "2021-09-14T00:00:00.000000Z",
      "revision_history": [
        {
          "date": "2021-09-14T00:00:00.000000Z",
          "legacy_version": "1.0",
          "number": "1",
          "summary": "Publication Date"
        },
        {
          "date": "2025-05-06T06:00:00.000000Z",
          "legacy_version": "Revision",
          "number": "2",
          "summary": "Revision - Fixing typos"
        }
      ],
      "status": "final",
      "version": "2"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "\u003e=V2.6.3",
                "product": {
                  "name": "APOGEE MBC (PPC) (P2 Ethernet)",
                  "product_id": "CSAFPID-0001"
                }
              }
            ],
            "category": "product_name",
            "name": "APOGEE MBC (PPC) (P2 Ethernet)"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "\u003e=V2.6.3",
                "product": {
                  "name": "APOGEE MEC (PPC) (P2 Ethernet)",
                  "product_id": "CSAFPID-0002"
                }
              }
            ],
            "category": "product_name",
            "name": "APOGEE MEC (PPC) (P2 Ethernet)"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "\u003cV3.5.3",
                "product": {
                  "name": "APOGEE PXC Compact (BACnet)",
                  "product_id": "CSAFPID-0003"
                }
              }
            ],
            "category": "product_name",
            "name": "APOGEE PXC Compact (BACnet)"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "\u003e=V2.8",
                "product": {
                  "name": "APOGEE PXC Compact (P2 Ethernet)",
                  "product_id": "CSAFPID-0004"
                }
              }
            ],
            "category": "product_name",
            "name": "APOGEE PXC Compact (P2 Ethernet)"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "\u003cV3.5.3",
                "product": {
                  "name": "APOGEE PXC Modular (BACnet)",
                  "product_id": "CSAFPID-0005"
                }
              }
            ],
            "category": "product_name",
            "name": "APOGEE PXC Modular (BACnet)"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "\u003e=V2.8",
                "product": {
                  "name": "APOGEE PXC Modular (P2 Ethernet)",
                  "product_id": "CSAFPID-0006"
                }
              }
            ],
            "category": "product_name",
            "name": "APOGEE PXC Modular (P2 Ethernet)"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "\u003cV3.5.3",
                "product": {
                  "name": "TALON TC Compact (BACnet)",
                  "product_id": "CSAFPID-0007"
                }
              }
            ],
            "category": "product_name",
            "name": "TALON TC Compact (BACnet)"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "\u003cV3.5.3",
                "product": {
                  "name": "TALON TC Modular (BACnet)",
                  "product_id": "CSAFPID-0008"
                }
              }
            ],
            "category": "product_name",
            "name": "TALON TC Modular (BACnet)"
          }
        ],
        "category": "vendor",
        "name": "Siemens"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2021-27391",
      "cwe": {
        "id": "CWE-120",
        "name": "Buffer Copy without Checking Size of Input (\u0027Classic Buffer Overflow\u0027)"
      },
      "notes": [
        {
          "category": "summary",
          "text": "The web server of affected devices lacks proper bounds checking when parsing the Host parameter in HTTP requests, which could lead to a buffer overflow.\n\nAn unauthenticated remote attacker could exploit this vulnerability to execute arbitrary code on the device with root privileges.",
          "title": "Summary"
        }
      ],
      "product_status": {
        "known_affected": [
          "CSAFPID-0001",
          "CSAFPID-0002",
          "CSAFPID-0003",
          "CSAFPID-0004",
          "CSAFPID-0005",
          "CSAFPID-0006",
          "CSAFPID-0007",
          "CSAFPID-0008"
        ]
      },
      "references": [
        {
          "summary": "CVE-2021-27391 Mitre 5.0 json",
          "url": "https://cert-portal.siemens.com/productcert/mitre/CVE-2021-27391.json"
        }
      ],
      "remediations": [
        {
          "category": "none_available",
          "details": "Currently no remediation is available",
          "product_ids": [
            "CSAFPID-0001",
            "CSAFPID-0002",
            "CSAFPID-0004",
            "CSAFPID-0006"
          ]
        },
        {
          "category": "vendor_fix",
          "details": "Update to V3.5.3 or later version",
          "product_ids": [
            "CSAFPID-0003",
            "CSAFPID-0005",
            "CSAFPID-0007",
            "CSAFPID-0008"
          ]
        },
        {
          "category": "mitigation",
          "details": "Please contact your local Siemens office for support",
          "product_ids": [
            "CSAFPID-0001",
            "CSAFPID-0002",
            "CSAFPID-0003",
            "CSAFPID-0004",
            "CSAFPID-0005",
            "CSAFPID-0006",
            "CSAFPID-0007",
            "CSAFPID-0008"
          ]
        },
        {
          "category": "mitigation",
          "details": "Restrict access to the device, especially to the web interface (80/tcp and 443/tcp), to trusted IP addresses only",
          "product_ids": [
            "CSAFPID-0001",
            "CSAFPID-0002",
            "CSAFPID-0003",
            "CSAFPID-0004",
            "CSAFPID-0005",
            "CSAFPID-0006",
            "CSAFPID-0007",
            "CSAFPID-0008"
          ]
        },
        {
          "category": "mitigation",
          "details": "Disable the integrated web server",
          "product_ids": [
            "CSAFPID-0001",
            "CSAFPID-0002",
            "CSAFPID-0003",
            "CSAFPID-0004",
            "CSAFPID-0005",
            "CSAFPID-0006",
            "CSAFPID-0007",
            "CSAFPID-0008"
          ]
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:T/RC:C",
            "version": "3.1"
          },
          "products": [
            "CSAFPID-0001",
            "CSAFPID-0002",
            "CSAFPID-0003",
            "CSAFPID-0004",
            "CSAFPID-0005",
            "CSAFPID-0006",
            "CSAFPID-0007",
            "CSAFPID-0008"
          ]
        }
      ],
      "title": "CVE-2021-27391"
    }
  ]
}