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CVE-2023-54250

Estado: AplazadaAlta (8.2)—

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: avoid out of bounds access in decode_preauth_ctxt()

Confirm that the accessed pneg_ctxt->HashAlgorithms address sits within the SMB request boundary; deassemble_neg_contexts() only checks that the eight byte smb2_neg_context header + (client controlled) DataLength are within the packet boundary, which is insufficient.

Checking for sizeof(struct smb2_preauth_neg_context) is overkill given that the type currently assumes SMB311_SALT_SIZE bytes of trailing Salt.

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.

Vulnerabilidad en ksmbd (SMB server en Linux kernel) accesible remotamente sin autenticación (PR:N, UI:N, AV:N). Out-of-bounds read en decode_preauth_ctxt() permite DoS (A:H) o lectura de memoria kernel adyacente (C:L). Vector CVSS remoto sin privilegios → T1190.

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

Filter Network TrafficVulnerability ScanningPrivileged Account ManagementNetwork SegmentationLimit Access to Resource Over NetworkApplication Isolation and Sandboxing

Tecnologías afectadas (1)

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

Linux — Linux KernelAI

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2023-54250",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 8.2,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "LOW"
        },
        "impactScore": 4.2,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
              "lessThan": "39f5b4b313b445c980a2a295bed28228c29228ed",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
              "lessThan": "a2f6ded41bec1d3be643c80a5eb97f1680309001",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
              "lessThan": "f02edb9debbd36f44efa7567031485892c7df60d",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
              "lessThan": "e7067a446264a7514fa1cfaa4052cdb6803bc6a2",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "fs/ksmbd/smb2pdu.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.15"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "5.15",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "5.15.145",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "status": "unaffected",
              "version": "6.1.25",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.2.12",
              "versionType": "semver",
              "lessThanOrEqual": "6.2.*"
            },
            {
              "status": "unaffected",
              "version": "6.3",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "fs/ksmbd/smb2pdu.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2025-12-30T13:16:13.660",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/39f5b4b313b445c980a2a295bed28228c29228ed",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a2f6ded41bec1d3be643c80a5eb97f1680309001",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e7067a446264a7514fa1cfaa4052cdb6803bc6a2",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f02edb9debbd36f44efa7567031485892c7df60d",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Deferred",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: avoid out of bounds access in decode_preauth_ctxt()\n\nConfirm that the accessed pneg_ctxt->HashAlgorithms address sits within\nthe SMB request boundary; deassemble_neg_contexts() only checks that the\neight byte smb2_neg_context header + (client controlled) DataLength are\nwithin the packet boundary, which is insufficient.\n\nChecking for sizeof(struct smb2_preauth_neg_context) is overkill given\nthat the type currently assumes SMB311_SALT_SIZE bytes of trailing Salt."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nksmbd: evitar el acceso fuera de límites en decode_preauth_ctxt()\n\nConfirmar que la dirección pneg_ctxt->HashAlgorithms accedida se encuentra dentro del límite de la solicitud SMB; deassemble_neg_contexts() solo verifica que el encabezado smb2_neg_context de ocho bytes + (DataLength controlada por el cliente) estén dentro del límite del paquete, lo cual es insuficiente.\n\nVerificar sizeof(struct smb2_preauth_neg_context) es excesivo dado que el tipo actualmente asume SMB311_SALT_SIZE bytes de Salt final."
    }
  ],
  "lastModified": "2026-08-04T11:16:38.250",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}