{
    "data_version": "4.0",
    "data_type": "CVE",
    "data_format": "MITRE",
    "CVE_data_meta": {
        "ID": "CVE-2021-25677",
        "ASSIGNER": "productcert@siemens.com",
        "STATE": "PUBLIC"
    },
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "A vulnerability has been identified in APOGEE PXC Compact (BACnet) (All versions < V3.5.5), APOGEE PXC Compact (P2 Ethernet) (All versions < V2.8.20), APOGEE PXC Modular (BACnet) (All versions < V3.5.5), APOGEE PXC Modular (P2 Ethernet) (All versions < V2.8.20), Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions < V2017.02.3), Nucleus ReadyStart V3 (All versions < V2017.02.4), Nucleus ReadyStart V4 (All versions < V4.1.0), Nucleus Source Code (Versions including affected DNS modules), SIMOTICS CONNECT 400 (All versions < V0.5.0.0), SIMOTICS CONNECT 400 (All versions >= V0.5.0.0 < V1.0.0.0), TALON TC Compact (BACnet) (All versions < V3.5.5), TALON TC Modular (BACnet) (All versions < V3.5.5). The DNS client does not properly randomize DNS transaction IDs. That could allow an attacker to poison the DNS cache or spoof DNS resolving."
            }
        ]
    },
    "problemtype": {
        "problemtype_data": [
            {
                "description": [
                    {
                        "lang": "eng",
                        "value": "CWE-330: Use of Insufficiently Random Values",
                        "cweId": "CWE-330"
                    }
                ]
            }
        ]
    },
    "affects": {
        "vendor": {
            "vendor_data": [
                {
                    "vendor_name": "Siemens",
                    "product": {
                        "product_data": [
                            {
                                "product_name": "APOGEE PXC Compact (BACnet)",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "All versions < V3.5.5"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "APOGEE PXC Compact (P2 Ethernet)",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "All versions < V2.8.20"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "APOGEE PXC Modular (BACnet)",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "All versions < V3.5.5"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "APOGEE PXC Modular (P2 Ethernet)",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "All versions < V2.8.20"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Nucleus NET",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "All versions"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Nucleus ReadyStart V3",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "All versions < V2017.02.3"
                                        },
                                        {
                                            "version_affected": "=",
                                            "version_value": "All versions < V2017.02.4"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Nucleus ReadyStart V4",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "All versions < V4.1.0"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Nucleus Source Code",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "Versions including affected DNS modules"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "SIMOTICS CONNECT 400",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "All versions < V0.5.0.0"
                                        },
                                        {
                                            "version_affected": "=",
                                            "version_value": "All versions >= V0.5.0.0 < V1.0.0.0"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "TALON TC Compact (BACnet)",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "All versions < V3.5.5"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "TALON TC Modular (BACnet)",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "All versions < V3.5.5"
                                        }
                                    ]
                                }
                            }
                        ]
                    }
                }
            ]
        }
    },
    "references": {
        "reference_data": [
            {
                "url": "https://cert-portal.siemens.com/productcert/pdf/ssa-705111.pdf",
                "refsource": "MISC",
                "name": "https://cert-portal.siemens.com/productcert/pdf/ssa-705111.pdf"
            },
            {
                "url": "https://cert-portal.siemens.com/productcert/pdf/ssa-669158.pdf",
                "refsource": "MISC",
                "name": "https://cert-portal.siemens.com/productcert/pdf/ssa-669158.pdf"
            },
            {
                "url": "https://cert-portal.siemens.com/productcert/pdf/ssa-180579.pdf",
                "refsource": "MISC",
                "name": "https://cert-portal.siemens.com/productcert/pdf/ssa-180579.pdf"
            }
        ]
    },
    "impact": {
        "cvss": [
            {
                "version": "3.1",
                "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",
                "baseScore": 5.3,
                "baseSeverity": "MEDIUM"
            }
        ]
    }
}