{"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. Out of bounds event channels are available to 32-bit x86 domains. The so called 2-level event channel model imposes different limits on the number of usable event channels for 32-bit x86 domains vs 64-bit or Arm (either bitness) ones. 32-bit x86 domains can use only 1023 channels, due to limited space in their shared (between guest and Xen) information structure, whereas all other domains can use up to 4095 in this model. The recording of the respective limit during domain initialization, however, has occurred at a time where domains are still deemed to be 64-bit ones, prior to actually honoring respective domain properties. At the point domains get recognized as 32-bit ones, the limit didn't get updated accordingly. Due to this misbehavior in Xen, 32-bit domains (including Domain 0) servicing other domains may observe event channel allocations to succeed when they should really fail. Subsequent use of such event channels would then possibly lead to corruption of other parts of the shared info structure. An unprivileged guest may cause another domain, in particular Domain 0, to misbehave. This may lead to a Denial of Service (DoS) for the entire system. All Xen versions from 4.4 onwards are vulnerable. Xen versions 4.3 and earlier are not vulnerable. Only x86 32-bit domains servicing other domains are vulnerable. Arm systems, as well as x86 64-bit domains, are not vulnerable."}], "problemTypes": [{"descriptions": [{"description": "n/a", "lang": "en", "type": "text"}]}], "providerMetadata": {"dateUpdated": "2020-11-11T05:06:40", "orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "shortName": "mitre"}, "references": [{"tags": ["x_refsource_MISC"], "url": "https://xenbits.xen.org/xsa/advisory-342.html"}, {"name": "FEDORA-2020-306b84fd07", "tags": ["vendor-advisory", "x_refsource_FEDORA"], "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4JRXMKEMQRQYWYEPHVBIWUEAVQ3LU4FN/"}, {"name": "FEDORA-2020-f668e579be", "tags": ["vendor-advisory", "x_refsource_FEDORA"], "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DA633Y3G5KX7MKRN4PFEGM3IVTJMBEOM/"}, {"name": "DSA-4769", "tags": ["vendor-advisory", "x_refsource_DEBIAN"], "url": "https://www.debian.org/security/2020/dsa-4769"}, {"name": "openSUSE-SU-2020:1608", "tags": ["vendor-advisory", "x_refsource_SUSE"], "url": "http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00008.html"}, {"name": "FEDORA-2020-d46fe34349", "tags": ["vendor-advisory", "x_refsource_FEDORA"], "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RJZERRBJN6E6STDCHT4JHP4MI6TKBCJE/"}, {"name": "GLSA-202011-06", "tags": ["vendor-advisory", "x_refsource_GENTOO"], "url": "https://security.gentoo.org/glsa/202011-06"}], "x_legacyV4Record": {"CVE_data_meta": {"ASSIGNER": "cve@mitre.org", "ID": "CVE-2020-25600", "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. Out of bounds event channels are available to 32-bit x86 domains. The so called 2-level event channel model imposes different limits on the number of usable event channels for 32-bit x86 domains vs 64-bit or Arm (either bitness) ones. 32-bit x86 domains can use only 1023 channels, due to limited space in their shared (between guest and Xen) information structure, whereas all other domains can use up to 4095 in this model. The recording of the respective limit during domain initialization, however, has occurred at a time where domains are still deemed to be 64-bit ones, prior to actually honoring respective domain properties. At the point domains get recognized as 32-bit ones, the limit didn't get updated accordingly. Due to this misbehavior in Xen, 32-bit domains (including Domain 0) servicing other domains may observe event channel allocations to succeed when they should really fail. Subsequent use of such event channels would then possibly lead to corruption of other parts of the shared info structure. An unprivileged guest may cause another domain, in particular Domain 0, to misbehave. This may lead to a Denial of Service (DoS) for the entire system. All Xen versions from 4.4 onwards are vulnerable. Xen versions 4.3 and earlier are not vulnerable. Only x86 32-bit domains servicing other domains are vulnerable. Arm systems, as well as x86 64-bit domains, are not vulnerable."}]}, "problemtype": {"problemtype_data": [{"description": [{"lang": "eng", "value": "n/a"}]}]}, "references": {"reference_data": [{"name": "https://xenbits.xen.org/xsa/advisory-342.html", "refsource": "MISC", "url": "https://xenbits.xen.org/xsa/advisory-342.html"}, {"name": "FEDORA-2020-306b84fd07", "refsource": "FEDORA", "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/4JRXMKEMQRQYWYEPHVBIWUEAVQ3LU4FN/"}, {"name": "FEDORA-2020-f668e579be", "refsource": "FEDORA", "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DA633Y3G5KX7MKRN4PFEGM3IVTJMBEOM/"}, {"name": "DSA-4769", "refsource": "DEBIAN", "url": "https://www.debian.org/security/2020/dsa-4769"}, {"name": "openSUSE-SU-2020:1608", "refsource": "SUSE", "url": "http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00008.html"}, {"name": "FEDORA-2020-d46fe34349", "refsource": "FEDORA", "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/RJZERRBJN6E6STDCHT4JHP4MI6TKBCJE/"}, {"name": "GLSA-202011-06", "refsource": "GENTOO", "url": "https://security.gentoo.org/glsa/202011-06"}]}}}, "adp": [{"providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T15:33:05.687Z"}, "title": "CVE Program Container", "references": [{"tags": ["x_refsource_MISC", "x_transferred"], "url": "https://xenbits.xen.org/xsa/advisory-342.html"}, {"name": "FEDORA-2020-306b84fd07", "tags": ["vendor-advisory", "x_refsource_FEDORA", "x_transferred"], "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4JRXMKEMQRQYWYEPHVBIWUEAVQ3LU4FN/"}, {"name": "FEDORA-2020-f668e579be", "tags": ["vendor-advisory", "x_refsource_FEDORA", "x_transferred"], "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DA633Y3G5KX7MKRN4PFEGM3IVTJMBEOM/"}, {"name": "DSA-4769", "tags": ["vendor-advisory", "x_refsource_DEBIAN", "x_transferred"], "url": "https://www.debian.org/security/2020/dsa-4769"}, {"name": "openSUSE-SU-2020:1608", "tags": ["vendor-advisory", "x_refsource_SUSE", "x_transferred"], "url": "http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00008.html"}, {"name": "FEDORA-2020-d46fe34349", "tags": ["vendor-advisory", "x_refsource_FEDORA", "x_transferred"], "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RJZERRBJN6E6STDCHT4JHP4MI6TKBCJE/"}, {"name": "GLSA-202011-06", "tags": ["vendor-advisory", "x_refsource_GENTOO", "x_transferred"], "url": "https://security.gentoo.org/glsa/202011-06"}]}]}, "cveMetadata": {"assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "assignerShortName": "mitre", "cveId": "CVE-2020-25600", "datePublished": "2020-09-23T21:12:24", "dateReserved": "2020-09-16T00:00:00", "dateUpdated": "2024-08-04T15:33:05.687Z", "state": "PUBLISHED"}, "dataType": "CVE_RECORD", "dataVersion": "5.1"}

{}

{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:xen:xen:*:*:*:*:*:*:x86:*", "matchCriteriaId": "B5C63110-59F4-4309-8807-49289669222A", "versionEndIncluding": "4.14.0", "versionStartIncluding": "4.4.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}, {"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*", "matchCriteriaId": "80F0FA5D-8D3B-4C0E-81E2-87998286AF33", "vulnerable": true}, {"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"}]}, {"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:*", "matchCriteriaId": "B009C22E-30A4-4288-BCF6-C3E81DEAF45A", "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"}]}], "descriptions": [{"lang": "en", "value": "An issue was discovered in Xen through 4.14.x. Out of bounds event channels are available to 32-bit x86 domains. The so called 2-level event channel model imposes different limits on the number of usable event channels for 32-bit x86 domains vs 64-bit or Arm (either bitness) ones. 32-bit x86 domains can use only 1023 channels, due to limited space in their shared (between guest and Xen) information structure, whereas all other domains can use up to 4095 in this model. The recording of the respective limit during domain initialization, however, has occurred at a time where domains are still deemed to be 64-bit ones, prior to actually honoring respective domain properties. At the point domains get recognized as 32-bit ones, the limit didn't get updated accordingly. Due to this misbehavior in Xen, 32-bit domains (including Domain 0) servicing other domains may observe event channel allocations to succeed when they should really fail. Subsequent use of such event channels would then possibly lead to corruption of other parts of the shared info structure. An unprivileged guest may cause another domain, in particular Domain 0, to misbehave. This may lead to a Denial of Service (DoS) for the entire system. All Xen versions from 4.4 onwards are vulnerable. Xen versions 4.3 and earlier are not vulnerable. Only x86 32-bit domains servicing other domains are vulnerable. Arm systems, as well as x86 64-bit domains, are not vulnerable."}, {"lang": "es", "value": "Se detect\u00f3 un problema en Xen versiones hasta 4.14.x. Los canales de eventos fuera de l\u00edmites est\u00e1n disponibles para dominios x86 de 32 bits. El llamado modelo de canal de eventos de 2 niveles impone diferentes l\u00edmites en el n\u00famero de canales de eventos utilizables para dominios x86 de 32 bits frente a los de 64 bits o Arm (cualquiera de los dos). Los dominios x86 de 32 bits solo pueden usar 1023 canales, debido al espacio limitado en su estructura de informaci\u00f3n compartida (entre invitados y Xen), mientras que todos los dem\u00e1s dominios pueden usar hasta 4095 en este modelo. Sin embargo, el registro del l\u00edmite respectivo durante la inicializaci\u00f3n del dominio ha ocurrido en un momento en el que a\u00fan se considera que los dominios son de 64 bits, antes de respetar realmente las propiedades del dominio respectivo. En el momento en que los dominios se reconocen como de 32 bits, el l\u00edmite no logr\u00f3 actualizarse en consecuencia. Debido a este comportamiento inapropiado en Xen, los dominios de 32 bits (incluido el Dominio 0) que prestan servicio a otros dominios pueden observar que las asignaciones de canales de eventos tienen \u00e9xito cuando realmente deber\u00edan presentar un fallo. El uso posterior de dichos canales de eventos posiblemente conducir\u00eda a una corrupci\u00f3n de otras partes de la estructura de informaci\u00f3n compartida. Un invitado sin privilegios puede hacer que otro dominio, en particular el Dominio 0, se comporte incorrectamente. Esto puede conllevar a una Denegaci\u00f3n de servicio (DoS) para todo el sistema. Todas las versiones de Xen desde 4.4 en adelante son vulnerables. Las versiones 4.3 y anteriores de Xen no son vulnerables. Solo los dominios x86 de 32 bits que dan servicio a otros dominios son vulnerables. Los sistemas Arm, as\u00ed como los dominios x86 de 64 bits, no son vulnerables. Un invitado sin privilegios puede hacer que otro dominio, en particular el Dominio 0, se comporte mal. Esto puede conllevar a una Denegaci\u00f3n de servicio (DoS) para todo el sistema. Todas las versiones de Xen desde 4.4 en adelante son vulnerables. Las versiones 4.3 y anteriores de Xen no son vulnerables. Solo los dominios x86 de 32 bits que dan servicio a otros dominios son vulnerables. Los sistemas Arm, as\u00ed como los dominios x86 de 64 bits, no son vulnerables. Un invitado sin privilegios puede hacer que otro dominio, en particular el Dominio 0, se comporte mal. Esto puede conllevar a una Denegaci\u00f3n de Servicio (DoS) para todo el sistema. Todas las versiones de Xen desde 4.4 en adelante son vulnerables. Las versiones 4.3 y anteriores de Xen no son vulnerables. Solo los dominios x86 de 32 bits que dan servicio a otros dominios son vulnerables. Los sistemas Arm, as\u00ed como los dominios x86 de 64 bits, no son vulnerables."}], "id": "CVE-2020-25600", "lastModified": "2024-11-21T05:18:12.297", "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": "2020-09-23T22:15:13.603", "references": [{"source": "cve@mitre.org", "tags": ["Mailing List", "Third Party Advisory"], "url": "http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00008.html"}, {"source": "cve@mitre.org", "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4JRXMKEMQRQYWYEPHVBIWUEAVQ3LU4FN/"}, {"source": "cve@mitre.org", "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DA633Y3G5KX7MKRN4PFEGM3IVTJMBEOM/"}, {"source": "cve@mitre.org", "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RJZERRBJN6E6STDCHT4JHP4MI6TKBCJE/"}, {"source": "cve@mitre.org", "tags": ["Third Party Advisory"], "url": "https://security.gentoo.org/glsa/202011-06"}, {"source": "cve@mitre.org", "tags": ["Third Party Advisory"], "url": "https://www.debian.org/security/2020/dsa-4769"}, {"source": "cve@mitre.org", "tags": ["Vendor Advisory"], "url": "https://xenbits.xen.org/xsa/advisory-342.html"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Mailing List", "Third Party Advisory"], "url": "http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00008.html"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4JRXMKEMQRQYWYEPHVBIWUEAVQ3LU4FN/"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DA633Y3G5KX7MKRN4PFEGM3IVTJMBEOM/"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RJZERRBJN6E6STDCHT4JHP4MI6TKBCJE/"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Third Party Advisory"], "url": "https://security.gentoo.org/glsa/202011-06"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Third Party Advisory"], "url": "https://www.debian.org/security/2020/dsa-4769"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Vendor Advisory"], "url": "https://xenbits.xen.org/xsa/advisory-342.html"}], "sourceIdentifier": "cve@mitre.org", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-787"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"acknowledgement": "Red Hat would like to thank the Xen project for reporting this issue.", "bugzilla": {"description": "xen: out of bounds event channels available to 32-bit x86 domains (XSA-342)", "id": "1880156", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1880156"}, "csaw": false, "cvss3": {"cvss3_base_score": "6.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-440", "details": ["An issue was discovered in Xen through 4.14.x. Out of bounds event channels are available to 32-bit x86 domains. The so called 2-level event channel model imposes different limits on the number of usable event channels for 32-bit x86 domains vs 64-bit or Arm (either bitness) ones. 32-bit x86 domains can use only 1023 channels, due to limited space in their shared (between guest and Xen) information structure, whereas all other domains can use up to 4095 in this model. The recording of the respective limit during domain initialization, however, has occurred at a time where domains are still deemed to be 64-bit ones, prior to actually honoring respective domain properties. At the point domains get recognized as 32-bit ones, the limit didn't get updated accordingly. Due to this misbehavior in Xen, 32-bit domains (including Domain 0) servicing other domains may observe event channel allocations to succeed when they should really fail. Subsequent use of such event channels would then possibly lead to corruption of other parts of the shared info structure. An unprivileged guest may cause another domain, in particular Domain 0, to misbehave. This may lead to a Denial of Service (DoS) for the entire system. All Xen versions from 4.4 onwards are vulnerable. Xen versions 4.3 and earlier are not vulnerable. Only x86 32-bit domains servicing other domains are vulnerable. Arm systems, as well as x86 64-bit domains, are not vulnerable.", "A flaw was found in Xen. Misbehavior during domain initialization, where 32-bit domains (including Domain 0) servicing other domains, may observe event channel allocations to succeed when they should fail. Subsequent use of such event channels leads to the corruption of other parts of the shared information structure. This flaw allows an unprivileged guest to crash another domain, particularly Domain 0, leading to a denial of service (DoS) for the entire system. The highest threat from this vulnerability is to system availability."], "mitigation": {"lang": "en:us", "value": "There is no known workaround for x86 32-bit Domain 0. The issue can be avoided by reducing the number of event channels available to the guest to no more than 1023. For example, setting `max_event_channels=1023` in the xl domain configuration, or deleting any existing setting (since 1023 is the default for xl/libxl)."}, "name": "CVE-2020-25600", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:5", "fix_state": "Not affected", "package_name": "kernel-xen", "product_name": "Red Hat Enterprise Linux 5"}], "public_date": "2020-09-22T12:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2020-25600\nhttps://nvd.nist.gov/vuln/detail/CVE-2020-25600\nhttps://xenbits.xen.org/xsa/advisory-342.html"], "statement": "All Xen versions from 4.4 onwards are vulnerable. Red Hat Enterprise Linux 5 is not affected by this flaw, as it shipped with an older version of Xen.", "threat_severity": "Moderate"}