CVE-2023-43636

{"id": "CVE-2023-43636", "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 8.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "impactScore": 6.0, "exploitabilityScore": 2.0}, {"type": "Secondary", "source": "cve@asrg.io", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 8.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "impactScore": 6.0, "exploitabilityScore": 2.0}]}, "published": "2023-09-20T15:15:12.063", "references": [{"url": "https://asrg.io/security-advisories/cve-2023-43636/", "source": "cve@asrg.io"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-345"}]}, {"type": "Secondary", "source": "cve@asrg.io", "description": [{"lang": "en", "value": "CWE-345"}]}], "descriptions": [{"lang": "en", "value": "\n\n\nIn EVE OS, the \u201cmeasured boot\u201d mechanism prevents a compromised device from accessing\nthe encrypted data located in the vault.\n\nAs per the \u201cmeasured boot\u201d design, the PCR values calculated at different stages of the boot\nprocess will change if any of their respective parts are changed.\n\nThis includes, among other things, the configuration of the bios, grub, the kernel cmdline,\ninitrd, and more.\n\nHowever, this mechanism does not validate the entire rootfs, so an attacker can edit the\nfilesystem and gain control over the system.\n\nAs the default filesystem used by EVE OS is squashfs, this is somewhat harder than an ext4,\nwhich is easily changeable.\n\nThis will not stop an attacker, as an attacker can repackage the squashfs with their changes\nin it and replace the partition altogether.\n\nThis can also be done directly on the device, as the \u201c003-storage-init\u201d container contains the\n\u201cmksquashfs\u201d and \u201cunsquashfs\u201d binaries (with the corresponding libs).\n\n\n\n\n\n\n\nAn attacker can gain full control over the device without changing the PCR values, thus not\ntriggering the \u201cmeasured boot\u201d mechanism, and having full access to the vault.\n\n\n\nNote:\n\nThis issue was partially fixed in these commits (after disclosure to Zededa), where the config\npartition measurement was added to PCR13:\n\n\u2022 aa3501d6c57206ced222c33aea15a9169d629141\n\n\u2022 5fef4d92e75838cc78010edaed5247dfbdae1889.\n\nThis issue was made viable in version 9.0.0 when the calculation was moved to PCR14 but it was not included in the measured boot."}, {"lang": "es", "value": "En EVE OS, el mecanismo de \"measured boot\" evita que un dispositivo comprometido acceda a los datos cifrados ubicados en la b\u00f3veda. Seg\u00fan el dise\u00f1o de \u201cmeasured boot\u201d, los valores de PCR calculados en diferentes etapas del proceso de arranque cambiar\u00e1n si se cambia alguna de sus respectivas partes. Esto incluye, entre otras cosas, la configuraci\u00f3n de BIOS, grub, cmdline del kernel, initrd y m\u00e1s. Sin embargo, este mecanismo no valida todos los rootfs, por lo que un atacante puede editar el sistema de archivos y obtener control sobre el sistema. Como el sistema de archivos predeterminado utilizado por EVE OS es squashfs, esto es algo m\u00e1s dif\u00edcil que un ext4, que se puede cambiar f\u00e1cilmente. Esto no detendr\u00e1 a un atacante, ya que un atacante puede volver a empaquetar los squashfs con sus cambios y reemplazar la partici\u00f3n por completo. Esto tambi\u00e9n se puede hacer directamente en el dispositivo, ya que el contenedor \u201c003-storage-init\u201d contiene los binarios \u201cmksquashfs\u201d y \u201cunsquashfs\u201d (con las bibliotecas correspondientes). Un atacante puede obtener control total sobre el dispositivo sin cambiar los valores de PCR, por lo que no activar\u00e1 el mecanismo de \"measured boot\" y tendr\u00e1 acceso completo a la b\u00f3veda. Nota: Este problema se solucion\u00f3 parcialmente en estos commits (despu\u00e9s de la divulgaci\u00f3n a Zededa), donde la medici\u00f3n de la partici\u00f3n de configuraci\u00f3n se agreg\u00f3 a PCR13: \n\u2022 aa3501d6c57206ced222c33aea15a9169d629141 \n\u2022 5fef4d92e75838cc78010edaed5247dfbdae1889\nEste problema se hizo viable en la versi\u00f3n 9.0.0 cuando el c\u00e1lculo se traslad\u00f3 a PCR14, pero no se incluy\u00f3 en el \"measured boot\"."}], "lastModified": "2023-09-28T06:15:13.473", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linuxfoundation:edge_virtualization_engine:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "A569C358-B746-494B-A5EE-15D38BD74AB2", "versionEndExcluding": "8.6.0"}, {"criteria": "cpe:2.3:o:linuxfoundation:edge_virtualization_engine:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "D19A1245-092C-478C-BB01-23F91A227B3F", "versionEndExcluding": "9.5.0", "versionStartIncluding": "9.0.0"}], "operator": "OR"}]}], "sourceIdentifier": "cve@asrg.io"}