{"dataType": "CVE_RECORD", "dataVersion": "5.0", "cveMetadata": {"cveId": "CVE-2023-46836", "assignerOrgId": "23aa2041-22e1-471f-9209-9b7396fa234f", "state": "PUBLISHED", "assignerShortName": "XEN", "dateReserved": "2023-10-27T07:55:35.332Z", "datePublished": "2024-01-05T16:34:59.036Z", "dateUpdated": "2024-01-05T16:34:59.036Z"}, "containers": {"cna": {"title": "x86: BTC/SRSO fixes not fully effective", "datePublic": "2023-11-14T12:00:00Z", "descriptions": [{"lang": "en", "value": "The fixes for XSA-422 (Branch Type Confusion) and XSA-434 (Speculative\nReturn Stack Overflow) are not IRQ-safe. It was believed that the\nmitigations always operated in contexts with IRQs disabled.\n\nHowever, the original XSA-254 fix for Meltdown (XPTI) deliberately left\ninterrupts enabled on two entry paths; one unconditionally, and one\nconditionally on whether XPTI was active.\n\nAs BTC/SRSO and Meltdown affect different CPU vendors, the mitigations\nare not active together by default. Therefore, there is a race\ncondition whereby a malicious PV guest can bypass BTC/SRSO protections\nand launch a BTC/SRSO attack against Xen.\n"}], "impacts": [{"descriptions": [{"lang": "en", "value": "An attacker in a PV guest might be able to infer the contents of memory\nbelonging to other guests.\n"}]}], "affected": [{"defaultStatus": "unknown", "product": "Xen", "vendor": "Xen", "versions": [{"status": "unknown", "version": "consult Xen advisory XSA-446"}]}], "configurations": [{"lang": "en", "value": "All versions of Xen are vulnerable.\n\nXen is only vulnerable in default configurations on AMD and Hygon CPUs.\n\nXen is not believed to be vulnerable in default configurations on CPUs\nfrom other hardware vendors.\n\nOnly PV guests can leverage the vulnerability.\n"}], "workarounds": [{"lang": "en", "value": "Running only HVM or PVH VMs will avoid the vulnerability.\n"}], "credits": [{"lang": "en", "type": "finder", "value": "This issue was discovered by Andrew Cooper of XenServer.\n"}], "references": [{"url": "https://xenbits.xenproject.org/xsa/advisory-446.html"}], "providerMetadata": {"orgId": "23aa2041-22e1-471f-9209-9b7396fa234f", "shortName": "XEN", "dateUpdated": "2024-01-05T16:34:59.036Z"}}}}

{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:*", "matchCriteriaId": "C2B9CCC2-BAC5-4A65-B8D4-4B71EBBA0C2F", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "descriptions": [{"lang": "en", "value": "The fixes for XSA-422 (Branch Type Confusion) and XSA-434 (Speculative\nReturn Stack Overflow) are not IRQ-safe. It was believed that the\nmitigations always operated in contexts with IRQs disabled.\n\nHowever, the original XSA-254 fix for Meltdown (XPTI) deliberately left\ninterrupts enabled on two entry paths; one unconditionally, and one\nconditionally on whether XPTI was active.\n\nAs BTC/SRSO and Meltdown affect different CPU vendors, the mitigations\nare not active together by default. Therefore, there is a race\ncondition whereby a malicious PV guest can bypass BTC/SRSO protections\nand launch a BTC/SRSO attack against Xen.\n"}, {"lang": "es", "value": "Las correcciones para XSA-422 (Branch Type Confusion) y XSA-434 (Speculative Return Stack Overflow) no son seguras para IRQ. Se cre\u00eda que las mitigaciones siempre operaban en contextos con las IRQ deshabilitadas. Sin embargo, la soluci\u00f3n XSA-254 original para Meltdown (XPTI) deliberadamente dej\u00f3 habilitadas las interrupciones en dos rutas de entrada; uno incondicionalmente y otro condicionalmente sobre si XPTI estaba activo. Como BTC/SRSO y Meltdown afectan a diferentes proveedores de CPU, las mitigaciones no est\u00e1n activas juntas de forma predeterminada. Por lo tanto, existe una condici\u00f3n de ejecuci\u00f3n mediante la cual un invitado PV malicioso puede eludir las protecciones BTC/SRSO y lanzar un ataque BTC/SRSO contra Xen."}], "id": "CVE-2023-46836", "lastModified": "2024-01-11T17:09:02.020", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "LOCAL", "availabilityImpact": "NONE", "baseScore": 4.7, "baseSeverity": "MEDIUM", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N", "version": "3.1"}, "exploitabilityScore": 1.0, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}]}, "published": "2024-01-05T17:15:11.197", "references": [{"source": "security@xen.org", "tags": ["Patch", "Vendor Advisory"], "url": "https://xenbits.xenproject.org/xsa/advisory-446.html"}], "sourceIdentifier": "security@xen.org", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "NVD-CWE-noinfo"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{}