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CVE-2026-43620

Estado: AnalizadaMedia (6.9)—

Rsync version 3.4.2 and prior contain a receiver-side out-of-bounds array read vulnerability in recv_files() in receiver.c that allows a malicious rsync server to crash the rsync client process. Attackers can exploit the vulnerability by setting CF_INC_RECURSE in compatibility flags and sending a specially crafted file list where the first sorted entry is not the leading dot directory, followed by a transfer record with ndx=0 and an iflag word without ITEM_TRANSFER, causing the receiver to read 8 bytes before the allocated pointer array and dereference an invalid pointer at an unmapped address, resulting in a deterministic SIGSEGV crash of the rsync client.

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).

Tecnologías afectadas (1)

Samba — Rsync

CWE

Referencias

JSON original (NVD)

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  "id": "CVE-2026-43620",
  "cveTags": [],
  "metrics": {
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        "ssvcData": {
          "id": "CVE-2026-43620",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-05-20T14:11:42.448773Z"
        }
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    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "disclosure@vulncheck.com",
        "cvssData": {
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          "attackVector": "NETWORK",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "REQUIRED",
          "attackComplexity": "LOW",
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          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
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        "cvssData": {
          "Safety": "NOT_DEFINED",
          "version": "4.0",
          "Recovery": "NOT_DEFINED",
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          "Automatable": "NOT_DEFINED",
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          "valueDensity": "NOT_DEFINED",
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          "exploitMaturity": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED",
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          "privilegesRequired": "NONE",
          "subIntegrityImpact": "NONE",
          "vulnIntegrityImpact": "NONE",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
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          "vulnAvailabilityImpact": "HIGH",
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          "modifiedAttackRequirements": "NOT_DEFINED",
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          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
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      "affectedData": [
        {
          "repo": "https://github.com/RsyncProject/rsync",
          "vendor": "RsyncProject",
          "product": "rsync",
          "versions": [
            {
              "status": "affected",
              "version": "0",
              "lessThan": "3.4.3",
              "versionType": "semver"
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          ],
          "packageURL": "pkg:github/RsyncProject/rsync",
          "defaultStatus": "unaffected"
        }
      ]
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  ],
  "published": "2026-05-20T02:16:36.727",
  "references": [
    {
      "url": "https://github.com/RsyncProject/rsync/releases/tag/v3.4.3",
      "tags": [
        "Release Notes"
      ],
      "source": "disclosure@vulncheck.com"
    },
    {
      "url": "https://github.com/RsyncProject/rsync/security/advisories/GHSA-28pw-r563-rxvm",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "disclosure@vulncheck.com"
    },
    {
      "url": "https://www.vulncheck.com/advisories/rsync-out-of-bounds-array-read-via-recv-files",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "disclosure@vulncheck.com"
    }
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  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
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      "source": "disclosure@vulncheck.com",
      "description": [
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          "value": "CWE-125"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Rsync version 3.4.2 and prior contain a receiver-side out-of-bounds array read vulnerability in recv_files() in receiver.c that allows a malicious rsync server to crash the rsync client process. Attackers can exploit the vulnerability by setting CF_INC_RECURSE in compatibility flags and sending a specially crafted file list where the first sorted entry is not the leading dot directory, followed by a transfer record with ndx=0 and an iflag word without ITEM_TRANSFER, causing the receiver to read 8 bytes before the allocated pointer array and dereference an invalid pointer at an unmapped address, resulting in a deterministic SIGSEGV crash of the rsync client."
    },
    {
      "lang": "es",
      "value": "La versión 3.4.2 de Rsync y anteriores contienen una vulnerabilidad de lectura de array fuera de límites en el lado del receptor en recv_files() en receiver.c que permite a un servidor rsync malicioso bloquear el proceso del cliente rsync. Los atacantes pueden explotar la vulnerabilidad al establecer CF_INC_RECURSE en los indicadores de compatibilidad y enviar una lista de archivos especialmente diseñada donde la primera entrada ordenada no es el directorio de punto inicial, seguido de un registro de transferencia con ndx=0 y una palabra iflag sin ITEM_TRANSFER, lo que hace que el receptor lea 8 bytes antes del array de punteros asignado y desreferencie un puntero inválido en una dirección no mapeada, lo que resulta en un bloqueo SIGSEGV determinista del cliente rsync."
    }
  ],
  "lastModified": "2026-07-24T09:10:00.153",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:samba:rsync:*:*:*:*:*:*:*:*",
              "vulnerable": true,
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              "versionEndIncluding": "3.4.2"
            }
          ],
          "operator": "OR"
        }
      ]
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  "sourceIdentifier": "disclosure@vulncheck.com"
}