CVE-2021-28704

{"id": "CVE-2021-28704", "metrics": {"cvssMetricV2": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"version": "2.0", "baseScore": 6.9, "accessVector": "LOCAL", "vectorString": "AV:L/AC:M/Au:N/C:C/I:C/A:C", "authentication": "NONE", "integrityImpact": "COMPLETE", "accessComplexity": "MEDIUM", "availabilityImpact": "COMPLETE", "confidentialityImpact": "COMPLETE"}, "acInsufInfo": false, "impactScore": 10.0, "baseSeverity": "MEDIUM", "obtainAllPrivilege": false, "exploitabilityScore": 3.4, "obtainUserPrivilege": false, "obtainOtherPrivilege": false, "userInteractionRequired": false}], "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}]}, "published": "2021-11-24T01:15:08.030", "references": [{"url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I7ZGWVVRI4XY2XSTBI3XEMWBXPDVX6OT/", "source": "security@xen.org"}, {"url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PXUI4VMD52CH3T7YXAG3J2JW7ZNN3SXF/", "source": "security@xen.org"}, {"url": "https://security.gentoo.org/glsa/202402-07", "source": "security@xen.org"}, {"url": "https://www.debian.org/security/2021/dsa-5017", "tags": ["Third Party Advisory"], "source": "security@xen.org"}, {"url": "https://xenbits.xenproject.org/xsa/advisory-388.txt", "tags": ["Patch", "Vendor Advisory"], "source": "security@xen.org"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "descriptions": [{"lang": "en", "value": "PoD operations on misaligned GFNs T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] x86 HVM and PVH guests may be started in populate-on-demand (PoD) mode, to provide a way for them to later easily have more memory assigned. Guests are permitted to control certain P2M aspects of individual pages via hypercalls. These hypercalls may act on ranges of pages specified via page orders (resulting in a power-of-2 number of pages). The implementation of some of these hypercalls for PoD does not enforce the base page frame number to be suitably aligned for the specified order, yet some code involved in PoD handling actually makes such an assumption. These operations are XENMEM_decrease_reservation (CVE-2021-28704) and XENMEM_populate_physmap (CVE-2021-28707), the latter usable only by domains controlling the guest, i.e. a de-privileged qemu or a stub domain. (Patch 1, combining the fix to both these two issues.) In addition handling of XENMEM_decrease_reservation can also trigger a host crash when the specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708, patch 2)."}, {"lang": "es", "value": "Operaciones PoD en GFNs desalineados [Este registro de informaci\u00f3n CNA se relaciona con m\u00faltiples CVEs; el texto explica qu\u00e9 aspectos/vulnerabilidades corresponden a cada CVE. Los hu\u00e9spedes x86 HVM y PVH pueden iniciarse en modo populate-on-demand (PoD), para proporcionar una manera de que m\u00e1s tarde les sea asignado f\u00e1cilmente m\u00e1s memoria. A los hu\u00e9spedes les es permitido controlar determinados aspectos P2M de p\u00e1ginas individuales por medio de hypercalls. Estas hypercalls pueden actuar sobre rangos de p\u00e1ginas especificados por medio de \u00f3rdenes de p\u00e1ginas (resultando en un n\u00famero de p\u00e1ginas de potencia 2). La implementaci\u00f3n de algunas de estas hypercalls para PoD no obliga a que el n\u00famero de fotograma de la p\u00e1gina base est\u00e9 apropiadamente alineado para el orden especificado, aunque algunos c\u00f3digos involucrados en el manejo de PoD realmente hacen tal suposici\u00f3n. Estas operaciones son XENMEM_decrease_reservation (CVE-2021-28704) y XENMEM_populate_physmap (CVE-2021-28707), esta \u00faltima usable s\u00f3lo por los dominios que controlan el hu\u00e9sped, es decir, un qemu no privilegiado o un dominio stub. (Parche 1, que combina la correcci\u00f3n de estos dos problemas.) Adem\u00e1s, el manejo de XENMEM_decrease_reservation tambi\u00e9n puede desencadenar un bloqueo en el host cuando el orden de p\u00e1gina especificado no es ni 4k ni 2M ni 1G (CVE-2021-28708, parche 2)"}], "lastModified": "2024-02-04T08:15:08.623", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:xen:xen:*:*:*:*:*:*:x86:*", "vulnerable": true, "matchCriteriaId": "F23764AD-488F-4ABC-95D5-FC1F64E0BC2E", "versionEndIncluding": "4.15.1", "versionStartIncluding": "4.7.0"}], "operator": "OR"}]}, {"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "A930E247-0B43-43CB-98FF-6CE7B8189835"}, {"criteria": "cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "80E516C0-98A4-4ADE-B69F-66A772E2BAAA"}], "operator": "OR"}]}, {"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "DEECE5FC-CACF-4496-A3E7-164736409252"}], "operator": "OR"}]}], "sourceIdentifier": "security@xen.org"}