{"containers": {"cna": {"affected": [{"product": "n/a", "vendor": "n/a", "versions": [{"status": "affected", "version": "n/a"}]}], "descriptions": [{"lang": "en", "value": "An issue was discovered in Xen through 4.14.x. When they require assistance from the device model, x86 HVM guests must be temporarily de-scheduled. The device model will signal Xen when it has completed its operation, via an event channel, so that the relevant vCPU is rescheduled. If the device model were to signal Xen without having actually completed the operation, the de-schedule / re-schedule cycle would repeat. If, in addition, Xen is resignalled very quickly, the re-schedule may occur before the de-schedule was fully complete, triggering a shortcut. This potentially repeating process uses ordinary recursive function calls, and thus could result in a stack overflow. A malicious or buggy stubdomain serving a HVM guest can cause Xen to crash, resulting in a Denial of Service (DoS) to the entire host. Only x86 systems are affected. Arm systems are not affected. Only x86 stubdomains serving HVM guests can exploit the vulnerability."}], "problemTypes": [{"descriptions": [{"description": "n/a", "lang": "en", "type": "text"}]}], "providerMetadata": {"dateUpdated": "2021-07-12T04:06:10", "orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "shortName": "mitre"}, "references": [{"tags": ["x_refsource_MISC"], "url": "https://xenbits.xenproject.org/xsa/advisory-348.html"}, {"name": "DSA-4812", "tags": ["vendor-advisory", "x_refsource_DEBIAN"], "url": "https://www.debian.org/security/2020/dsa-4812"}, {"name": "FEDORA-2020-64859a826b", "tags": ["vendor-advisory", "x_refsource_FEDORA"], "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OBLV6L6Q24PPQ2CRFXDX4Q76KU776GKI/"}, {"name": "FEDORA-2020-df772b417b", "tags": ["vendor-advisory", "x_refsource_FEDORA"], "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2C6M6S3CIMEBACH6O7V4H2VDANMO6TVA/"}, {"name": "GLSA-202107-30", "tags": ["vendor-advisory", "x_refsource_GENTOO"], "url": "https://security.gentoo.org/glsa/202107-30"}], "x_legacyV4Record": {"CVE_data_meta": {"ASSIGNER": "cve@mitre.org", "ID": "CVE-2020-29566", "STATE": "PUBLIC"}, "affects": {"vendor": {"vendor_data": [{"product": {"product_data": [{"product_name": "n/a", "version": {"version_data": [{"version_value": "n/a"}]}}]}, "vendor_name": "n/a"}]}}, "data_format": "MITRE", "data_type": "CVE", "data_version": "4.0", "description": {"description_data": [{"lang": "eng", "value": "An issue was discovered in Xen through 4.14.x. When they require assistance from the device model, x86 HVM guests must be temporarily de-scheduled. The device model will signal Xen when it has completed its operation, via an event channel, so that the relevant vCPU is rescheduled. If the device model were to signal Xen without having actually completed the operation, the de-schedule / re-schedule cycle would repeat. If, in addition, Xen is resignalled very quickly, the re-schedule may occur before the de-schedule was fully complete, triggering a shortcut. This potentially repeating process uses ordinary recursive function calls, and thus could result in a stack overflow. A malicious or buggy stubdomain serving a HVM guest can cause Xen to crash, resulting in a Denial of Service (DoS) to the entire host. Only x86 systems are affected. Arm systems are not affected. Only x86 stubdomains serving HVM guests can exploit the vulnerability."}]}, "problemtype": {"problemtype_data": [{"description": [{"lang": "eng", "value": "n/a"}]}]}, "references": {"reference_data": [{"name": "https://xenbits.xenproject.org/xsa/advisory-348.html", "refsource": "MISC", "url": "https://xenbits.xenproject.org/xsa/advisory-348.html"}, {"name": "DSA-4812", "refsource": "DEBIAN", "url": "https://www.debian.org/security/2020/dsa-4812"}, {"name": "FEDORA-2020-64859a826b", "refsource": "FEDORA", "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/OBLV6L6Q24PPQ2CRFXDX4Q76KU776GKI/"}, {"name": "FEDORA-2020-df772b417b", "refsource": "FEDORA", "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2C6M6S3CIMEBACH6O7V4H2VDANMO6TVA/"}, {"name": "GLSA-202107-30", "refsource": "GENTOO", "url": "https://security.gentoo.org/glsa/202107-30"}]}}}}, "cveMetadata": {"assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "assignerShortName": "mitre", "cveId": "CVE-2020-29566", "datePublished": "2020-12-15T16:49:11", "dateReserved": "2020-12-04T00:00:00", "dateUpdated": "2021-07-12T04:06:10", "state": "PUBLISHED"}, "dataType": "CVE_RECORD", "dataVersion": "5.0"}

{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:xen:xen:*:*:*:*:*:*:x86:*", "matchCriteriaId": "5BCCA6BA-E5A5-4C9E-828A-790663E0A79D", "versionEndIncluding": "4.14.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}, {"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*", "matchCriteriaId": "07B237A9-69A3-4A9C-9DA0-4E06BD37AE73", "vulnerable": true}], "negate": false, "operator": "OR"}]}, {"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*", "matchCriteriaId": "36D96259-24BD-44E2-96D9-78CE1D41F956", "vulnerable": true}, {"criteria": "cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*", "matchCriteriaId": "E460AA51-FCDA-46B9-AE97-E6676AA5E194", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "descriptions": [{"lang": "en", "value": "An issue was discovered in Xen through 4.14.x. 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Only x86 stubdomains serving HVM guests can exploit the vulnerability."}, {"lang": "es", "value": "Se detect\u00f3 un problema en Xen versiones hasta 4.14.x. Cuando requieran asistencia del modelo de dispositivo, los invitados de HVM x86 deben ser desprogramados temporalmente. El modelo de dispositivo enviar\u00e1 una se\u00f1al a Xen cuando ha sido completado su funcionamiento, por medio de un canal de eventos, de modo que se reprograme la vCPU correspondiente. Si el modelo del dispositivo enviara una se\u00f1al a Xen sin haber completado realmente la operaci\u00f3n, el ciclo de reprogramaci\u00f3n / reprogramaci\u00f3n se repetir\u00eda. Si, adem\u00e1s, Xen se vuelve a llamar muy r\u00e1pidamente, la reprogramaci\u00f3n puede ocurrir antes de la desprogramaci\u00f3n se haya completado por completo, lo que activa un atajo. Este proceso potencialmente repetitivo utiliza llamadas de funci\u00f3n recursivas ordinarias y, por lo tanto, podr\u00eda resultar en un desbordamiento de la pila. Un subdominio malicioso o con errores que atiende a un invitado HVM puede hacer que Xen se bloquee, lo que resultar\u00e1 en una Denegaci\u00f3n de servicio (DoS) para todo el host. Solo los Sistemas x86 est\u00e1n afectados. Los Sistemas ARM no se est\u00e1n afectadas. Solo los stubdomains x86 que atienden a invitadores HVM pueden aprovechar la vulnerabilidad"}], "id": "CVE-2020-29566", "lastModified": "2023-11-07T03:21:31.790", "metrics": {"cvssMetricV2": [{"acInsufInfo": false, "baseSeverity": "MEDIUM", "cvssData": {"accessComplexity": "LOW", "accessVector": "LOCAL", "authentication": "NONE", "availabilityImpact": "COMPLETE", "baseScore": 4.9, "confidentialityImpact": "NONE", "integrityImpact": "NONE", "vectorString": "AV:L/AC:L/Au:N/C:N/I:N/A:C", "version": "2.0"}, "exploitabilityScore": 3.9, "impactScore": 6.9, "obtainAllPrivilege": false, "obtainOtherPrivilege": false, "obtainUserPrivilege": false, "source": "nvd@nist.gov", "type": "Primary", "userInteractionRequired": false}], "cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 5.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}]}, "published": "2020-12-15T17:15:14.550", "references": [{"source": "cve@mitre.org", "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2C6M6S3CIMEBACH6O7V4H2VDANMO6TVA/"}, {"source": "cve@mitre.org", "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OBLV6L6Q24PPQ2CRFXDX4Q76KU776GKI/"}, {"source": "cve@mitre.org", "tags": ["Third Party Advisory"], "url": "https://security.gentoo.org/glsa/202107-30"}, {"source": "cve@mitre.org", "tags": ["Third Party Advisory"], "url": "https://www.debian.org/security/2020/dsa-4812"}, {"source": "cve@mitre.org", "tags": ["Patch", "Vendor Advisory"], "url": "https://xenbits.xenproject.org/xsa/advisory-348.html"}], "sourceIdentifier": "cve@mitre.org", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-674"}], "source": "nvd@nist.gov", "type": "Primary"}]}

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