CVE-2019-18423

{"id": "CVE-2019-18423", "metrics": {"cvssMetricV2": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"version": "2.0", "baseScore": 8.5, "accessVector": "NETWORK", "vectorString": "AV:N/AC:M/Au:S/C:C/I:C/A:C", "authentication": "SINGLE", "integrityImpact": "COMPLETE", "accessComplexity": "MEDIUM", "availabilityImpact": "COMPLETE", "confidentialityImpact": "COMPLETE"}, "acInsufInfo": false, "impactScore": 10.0, "baseSeverity": "HIGH", "obtainAllPrivilege": false, "exploitabilityScore": 6.8, "obtainUserPrivilege": false, "obtainOtherPrivilege": false, "userInteractionRequired": false}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 8.8, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 2.8}]}, "published": "2019-10-31T14:15:11.137", "references": [{"url": "http://www.openwall.com/lists/oss-security/2019/10/31/4", "tags": ["Mailing List", "Patch", "Third Party Advisory"], "source": "cve@mitre.org"}, {"url": "http://xenbits.xen.org/xsa/advisory-301.html", "tags": ["Patch", "Vendor Advisory"], "source": "cve@mitre.org"}, {"url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2BQKX7M2RHCWDBKNPX4KEBI3MJIH6AYZ/", "source": "cve@mitre.org"}, {"url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I5WWPW4BSZDDW7VHU427XTVXV7ROOFFW/", "source": "cve@mitre.org"}, {"url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IZYATWNUGHRBG6I3TC24YHP5Y3J7I6KH/", "source": "cve@mitre.org"}, {"url": "https://seclists.org/bugtraq/2020/Jan/21", "tags": ["Mailing List", "Third Party Advisory"], "source": "cve@mitre.org"}, {"url": "https://security.gentoo.org/glsa/202003-56", "tags": ["Third Party Advisory"], "source": "cve@mitre.org"}, {"url": "https://www.debian.org/security/2020/dsa-4602", "tags": ["Third Party Advisory"], "source": "cve@mitre.org"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-193"}]}], "descriptions": [{"lang": "en", "value": "An issue was discovered in Xen through 4.12.x allowing ARM guest OS users to cause a denial of service via a XENMEM_add_to_physmap hypercall. p2m->max_mapped_gfn is used by the functions p2m_resolve_translation_fault() and p2m_get_entry() to sanity check guest physical frame. The rest of the code in the two functions will assume that there is a valid root table and check that with BUG_ON(). The function p2m_get_root_pointer() will ignore the unused top bits of a guest physical frame. This means that the function p2m_set_entry() will alias the frame. However, p2m->max_mapped_gfn will be updated using the original frame. It would be possible to set p2m->max_mapped_gfn high enough to cover a frame that would lead p2m_get_root_pointer() to return NULL in p2m_get_entry() and p2m_resolve_translation_fault(). Additionally, the sanity check on p2m->max_mapped_gfn is off-by-one allowing \"highest mapped + 1\" to be considered valid. However, p2m_get_root_pointer() will return NULL. The problem could be triggered with a specially crafted hypercall XENMEM_add_to_physmap{, _batch} followed by an access to an address (via hypercall or direct access) that passes the sanity check but cause p2m_get_root_pointer() to return NULL. A malicious guest administrator may cause a hypervisor crash, resulting in a Denial of Service (DoS). Xen version 4.8 and newer are vulnerable. Only Arm systems are vulnerable. x86 systems are not affected."}, {"lang": "es", "value": "Se detect\u00f3 un problema en Xen versiones hasta 4.12.x, permitiendo a usuarios del sistema operativo invitado de ARM causar una denegaci\u00f3n de servicio por medio de una hipercall Xmapme_add_to_physmap. p2m-)max_mapped_gfn es utilizado por las funciones p2m_resolve_translation_fault() y p2m_get_entry() para comprobar trama f\u00edsica del invitado. El resto del c\u00f3digo en las dos funciones asumir\u00e1 que existe una tabla root v\u00e1lida y lo comprobar\u00e1 con BUG_ON(). La funci\u00f3n p2m_get_root_pointer() ignorar\u00e1 los bits superiores no utilizados de una trama f\u00edsica de invitado. Esto significa que la funci\u00f3n p2m_set_entry() renombrar\u00e1 la trama. Sin embargo, p2m-)max_mapped_gfn ser\u00e1 actualizada utilizando la trama original. Ser\u00eda posible establecer p2m-)max_mapped_gfn lo suficientemente alto como para cubrir una trama que conllevar\u00eda a p2m_get_root_pointer() a devolver NULL en p2m_get_entry() y p2m_resolve_translation_fault(). Adicionalmente, la comprobaci\u00f3n de saneamiento en p2m-)max_mapped_gfn est\u00e1 por un paso permitiendo que el \"highest mapped + 1\" sea considerado v\u00e1lido. Sin embargo, p2m_get_root_pointer() devolver\u00e1 NULL. El problema podr\u00eda desencadenarse con una hipercall especialmente dise\u00f1ada XENMEM_add_to_physmap{, _batch} seguido de un acceso a una direcci\u00f3n (por medio de hipercall o acceso directo) que pasa la comprobaci\u00f3n de saneamiento pero hace que la funci\u00f3n p2m_get_root_pointer() devuelva NULL. Un administrador invitado malicioso puede causar un bloqueo del hipervisor, resultando en una Denegaci\u00f3n de Servicio (DoS). Xen versi\u00f3n 4.8 y mas recientes son vulnerables. Solo los sistemas Arm son vulnerables. Los sistemas x86 no est\u00e1n afectados."}], "lastModified": "2023-11-07T03:06:26.877", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:xen:xen:*:*:*:*:*:*:arm:*", "vulnerable": true, "matchCriteriaId": "1FA49523-1CE8-479F-AB23-0349569FA707", "versionEndIncluding": "4.12.1", "versionStartIncluding": "4.8"}], "operator": "OR"}]}, {"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "DEECE5FC-CACF-4496-A3E7-164736409252"}, {"criteria": "cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "07B237A9-69A3-4A9C-9DA0-4E06BD37AE73"}, {"criteria": "cpe:2.3:o:fedoraproject:fedora:29:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "D100F7CE-FC64-4CC6-852A-6136D72DA419"}, {"criteria": "cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "97A4B8DF-58DA-4AB6-A1F9-331B36409BA3"}, {"criteria": "cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "80F0FA5D-8D3B-4C0E-81E2-87998286AF33"}], "operator": "OR"}]}], "sourceIdentifier": "cve@mitre.org"}