{
    "id": "CVE-2021-27391",
    "published": "2021-09-14 11:15:23",
    "last_modified": "2026-06-17 03:44:46",
    "cvss_score": "9.8",
    "cvss_severity": "CRITICAL",
    "cvss_version": "3.1",
    "cvss_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
    "cwe": "CWE-120",
    "description": "A vulnerability has been identified in APOGEE MBC (PPC) (P2 Ethernet) (All versions >= V2.6.3), APOGEE MEC (PPC) (P2 Ethernet) (All versions >= V2.6.3), APOGEE PXC Compact (BACnet) (All versions < V3.5.3), APOGEE PXC Compact (P2 Ethernet) (All versions >= V2.8), APOGEE PXC Modular (BACnet) (All versions < V3.5.3), APOGEE PXC Modular (P2 Ethernet) (All versions >= V2.8), TALON TC Compact (BACnet) (All versions < V3.5.3), TALON TC Modular (BACnet) (All versions < V3.5.3). 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. An unauthenticated remote attacker could exploit this vulnerability to execute arbitrary code on the device with root privileges.",
    "epss_score": "0.03369",
    "epss_percentile": "0.88430",
    "kev": 0,
    "kev_due": null,
    "has_exploit": 0,
    "updated_at": "2026-10-09 18:17:28",
    "priority": {
        "rank": 3,
        "label": "In your normal cycle",
        "why": "Critical by CVSS (9.8), but no sign of active exploitation."
    },
    "products": [
        {
            "vendor": "siemens",
            "product": "apogee_mbc_\\(ppc\\)_\\(p2_ethernet\\)"
        },
        {
            "vendor": "siemens",
            "product": "apogee_mbc_\\(ppc\\)_\\(p2_ethernet\\)_firmware"
        },
        {
            "vendor": "siemens",
            "product": "apogee_mec_\\(ppc\\)_\\(p2_ethernet\\)"
        },
        {
            "vendor": "siemens",
            "product": "apogee_mec_\\(ppc\\)_\\(p2_ethernet\\)_firmware"
        },
        {
            "vendor": "siemens",
            "product": "apogee_pxc_bacnet_automation_controller"
        },
        {
            "vendor": "siemens",
            "product": "apogee_pxc_bacnet_automation_controller_firmware"
        },
        {
            "vendor": "siemens",
            "product": "apogee_pxc_compact_\\(p2_ethernet\\)"
        },
        {
            "vendor": "siemens",
            "product": "apogee_pxc_compact_\\(p2_ethernet\\)_firmware"
        },
        {
            "vendor": "siemens",
            "product": "apogee_pxc_modular_\\(bacnet\\)"
        },
        {
            "vendor": "siemens",
            "product": "apogee_pxc_modular_\\(bacnet\\)_firmware"
        },
        {
            "vendor": "siemens",
            "product": "apogee_pxc_modular_\\(p2_ethernet\\)"
        },
        {
            "vendor": "siemens",
            "product": "apogee_pxc_modular_\\(p2_ethernet\\)_firmware"
        },
        {
            "vendor": "siemens",
            "product": "talon_tc_compact_\\(bacnet\\)"
        },
        {
            "vendor": "siemens",
            "product": "talon_tc_compact_\\(bacnet\\)_firmware"
        },
        {
            "vendor": "siemens",
            "product": "talon_tc_modular_\\(bacnet\\)"
        },
        {
            "vendor": "siemens",
            "product": "talon_tc_modular_\\(bacnet\\)_firmware"
        }
    ],
    "kev_detail": null,
    "exploits": [],
    "refs_list": [
        "https://cert-portal.siemens.com/productcert/pdf/ssa-944498.pdf",
        "https://cert-portal.siemens.com/productcert/pdf/ssa-944498.pdf"
    ]
}