fkie_cve-2023-46836
Vulnerability from fkie_nvd
Published
2024-01-05 17:15
Modified
2025-06-03 15:15
Severity ?
4.7 (Medium) - CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
4.7 (Medium) - CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
Summary
The fixes for XSA-422 (Branch Type Confusion) and XSA-434 (Speculative Return Stack Overflow) are not IRQ-safe. It was believed that the mitigations always operated in contexts with IRQs disabled. However, the original XSA-254 fix for Meltdown (XPTI) deliberately left interrupts enabled on two entry paths; one unconditionally, and one conditionally on whether XPTI was active. As BTC/SRSO and Meltdown affect different CPU vendors, the mitigations are not active together by default. Therefore, there is a race condition whereby a malicious PV guest can bypass BTC/SRSO protections and launch a BTC/SRSO attack against Xen.
References
security@xen.orghttps://xenbits.xenproject.org/xsa/advisory-446.htmlPatch, Vendor Advisory
af854a3a-2127-422b-91ae-364da2661108https://xenbits.xenproject.org/xsa/advisory-446.htmlPatch, Vendor Advisory
Impacted products
Vendor Product Version
xen xen *


To clipboard 

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            {
              "criteria": "cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "C2B9CCC2-BAC5-4A65-B8D4-4B71EBBA0C2F",
              "vulnerable": true
            }
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          "operator": "OR"
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  "cveTags": [],
  "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": "2025-06-03T15:15:42.700",
  "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"
      },
      {
        "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": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary"
      }
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  "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"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
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        "Vendor Advisory"
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      "url": "https://xenbits.xenproject.org/xsa/advisory-446.html"
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  "sourceIdentifier": "security@xen.org",
  "vulnStatus": "Modified",
  "weaknesses": [
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      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}


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