CVE-2023-46842

Unlike 32-bit PV guests, HVM guests may switch freely between 64-bit and other modes. This in particular means that they may set registers used to pass 32-bit-mode hypercall arguments to values outside of the range 32-bit code would be able to set them to. When processing of hypercalls takes a considerable amount of time, the hypervisor may choose to invoke a hypercall continuation. Doing so involves putting (perhaps updated) hypercall arguments in respective registers. For guests not running in 64-bit mode this further involves a certain amount of translation of the values. Unfortunately internal sanity checking of these translated values assumes high halves of registers to always be clear when invoking a hypercall. When this is found not to be the case, it triggers a consistency check in the hypervisor and causes a crash.

CVSS v3 6.5 MEDIUM

6.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.0 / Impact : 4.0

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope CHANGED

References

Link	Resource
https://xenbits.xenproject.org/xsa/advisory-454.html
https://xenbits.xenproject.org/xsa/advisory-454.html

Configurations

No configuration.

History

No history.

Information

Published : 2024-05-16 14:15

Updated : 2024-12-04 17:15

NVD link : CVE-2023-46842

Mitre link : CVE-2023-46842

CVE.ORG link : CVE-2023-46842

JSON object : View

Products Affected

No product.

CWE

CWE-843

Access of Resource Using Incompatible Type ('Type Confusion')

{"id": "CVE-2023-46842", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 6.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 4.0, "exploitabilityScore": 2.0}]}, "published": "2024-05-16T14:15:08.317", "references": [{"url": "https://xenbits.xenproject.org/xsa/advisory-454.html", "source": "security@xen.org"}, {"url": "https://xenbits.xenproject.org/xsa/advisory-454.html", "source": "af854a3a-2127-422b-91ae-364da2661108"}], "vulnStatus": "Awaiting Analysis", "weaknesses": [{"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "description": [{"lang": "en", "value": "CWE-843"}]}], "descriptions": [{"lang": "en", "value": "Unlike 32-bit PV guests, HVM guests may switch freely between 64-bit and\nother modes. This in particular means that they may set registers used\nto pass 32-bit-mode hypercall arguments to values outside of the range\n32-bit code would be able to set them to.\n\nWhen processing of hypercalls takes a considerable amount of time,\nthe hypervisor may choose to invoke a hypercall continuation. Doing so\ninvolves putting (perhaps updated) hypercall arguments in respective\nregisters. For guests not running in 64-bit mode this further involves\na certain amount of translation of the values.\n\nUnfortunately internal sanity checking of these translated values\nassumes high halves of registers to always be clear when invoking a\nhypercall. When this is found not to be the case, it triggers a\nconsistency check in the hypervisor and causes a crash.\n"}, {"lang": "es", "value": "A diferencia de los hu\u00e9spedes PV de 32 bits, los hu\u00e9spedes HVM pueden cambiar libremente entre 64 bits y otros modos. Esto significa en particular que pueden configurar los registros utilizados para pasar argumentos de hiperllamada en modo de 32 bits a valores fuera del rango en el que el c\u00f3digo de 32 bits podr\u00eda configurarlos. Cuando el procesamiento de hiperllamadas toma una cantidad considerable de tiempo, el hipervisor puede optar por invocar una continuaci\u00f3n de hiperllamada. Hacerlo implica colocar argumentos de hiperllamada (quiz\u00e1s actualizados) en los registros respectivos. Para los hu\u00e9spedes que no se ejecutan en modo de 64 bits, esto implica adem\u00e1s una cierta cantidad de traducci\u00f3n de los valores. Desafortunadamente, la comprobaci\u00f3n de cordura interna de estos valores traducidos supone que las mitades altas de los registros siempre est\u00e1n limpias al invocar una hiperllamada. Cuando se descubre que este no es el caso, se activa una comprobaci\u00f3n de coherencia en el hipervisor y se produce un bloqueo."}], "lastModified": "2024-12-04T17:15:11.343", "sourceIdentifier": "security@xen.org"}