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CVE-2026-82964

Estado: Pendiente de análisisAlta (8.8)—

Improper preservation of permissions in the Avast sandbox minifilter driver (aswSnx.sys) on Windows allows a local, low-privileged attacker executing inside the sandbox to escape file isolation and escalate to SYSTEM.

When the sandbox virtualizes a file it copies the original security descriptor, but the driver opened the virtualization target object with GENERIC_WRITE and FILE_WRITE_ATTRIBUTES only, omitting WRITE_DAC. Every attempt to apply the original DACL therefore failed, and the failure was discarded silently, leaving virtualized copies of sensitive files with permissive permissions.

Leer descripción completaMostrar menos

Because the IRP_MJ_CREATE callback additionally did not strip WRITE_DAC for sensitive directories, a sandboxed process could rewrite the security descriptor of a virtualized object, read the virtualized copy of the SAM database, extract local NTLM password hashes and execute code as SYSTEM.

The absence of an IRP_MJ_SET_SECURITY callback in the driver's operation registration table is a related defense-in-depth gap, but it is not the control that prevents this attack.

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

Escalada local desde privilegios bajos explotando permisos incorrectos en el driver (CWE-281, CWE-862). Permite leer SAM y ejecutar código como SYSTEM.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Execution PreventionThreat Intelligence ProgramPrivileged Account ManagementPassword PoliciesMulti-factor AuthenticationDisable or Remove Feature or Program

Tecnologías afectadas (1)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Avast — Sandbox Minifilter DriverAI

CWE

Referencias

JSON original (NVD)

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{
  "id": "CVE-2026-82964",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-82964",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-09-17T18:41:32.262077Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "security@nortonlifelock.com",
        "cvssData": {
          "scope": "CHANGED",
          "version": "3.1",
          "baseScore": 8.8,
          "attackVector": "LOCAL",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 6,
        "exploitabilityScore": 2
      }
    ]
  },
  "affected": [
    {
      "source": "security@nortonlifelock.com",
      "affectedData": [
        {
          "vendor": "Gen Digital",
          "product": "Avast Free Antivirus, Avast One, Avast Premium Security, Avast Ultimate, Avast Business Security",
          "versions": [
            {
              "status": "affected",
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  "published": "2026-09-16T15:17:55.837",
  "references": [
    {
      "url": "https://github.com/MSNightmare/PrettyPrague",
      "source": "security@nortonlifelock.com"
    },
    {
      "url": "https://support.avast.com/en-us/article/Update-Antivirus",
      "source": "security@nortonlifelock.com"
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    {
      "url": "https://support.avg.com/SupportArticleView?l=en&urlname=Update-AVG-Antivirus",
      "source": "security@nortonlifelock.com"
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    {
      "url": "https://support.norton.com/sp/en/us/home/current/solutions/v20240108175512167",
      "source": "security@nortonlifelock.com"
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    {
      "url": "https://www.gendigital.com/us/en/contact-us/security-advisories/",
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      "url": "https://x.com/msnightmare2000/status/2094106041046765752",
      "source": "security@nortonlifelock.com"
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  "vulnStatus": "Awaiting Analysis",
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      "description": [
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          "value": "CWE-281"
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        {
          "lang": "en",
          "value": "CWE-653"
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          "lang": "en",
          "value": "CWE-862"
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    {
      "lang": "en",
      "value": "Improper preservation of permissions in the Avast sandbox minifilter driver (aswSnx.sys) on Windows allows a local, low-privileged attacker executing inside the sandbox to escape file isolation and escalate to SYSTEM.\n\n\n\nWhen the sandbox virtualizes a file it copies the original security descriptor, but the driver opened the virtualization target object with GENERIC_WRITE and FILE_WRITE_ATTRIBUTES only, omitting WRITE_DAC. Every attempt to apply the original DACL therefore failed, and the failure was discarded silently, leaving virtualized copies of sensitive files with permissive permissions. Because the IRP_MJ_CREATE callback additionally did not strip WRITE_DAC for sensitive directories, a sandboxed process could rewrite the security descriptor of a virtualized object, read the virtualized copy of the SAM database, extract local NTLM password hashes and execute code as SYSTEM.\n\n\n\nThe absence of an IRP_MJ_SET_SECURITY callback in the driver's operation registration table is a related defense-in-depth gap, but it is not the control that prevents this attack."
    }
  ],
  "lastModified": "2026-09-17T19:17:05.013",
  "sourceIdentifier": "security@nortonlifelock.com"
}