CVE-2021-43040

Estado: ModificadaAlta (8.8)—

An issue was discovered in Kaseya Unitrends Backup Appliance before 10.5.5. The privileged vaultServer could be leveraged to create arbitrary writable files, leading to privilege escalation.

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Puntuación base: 8.8

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 1.83%
Percentil entre todas las CVEs puntuadas: 78
Fecha de la puntuación: 6/10/2026

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)

Kaseya — Unitrends Backup

CWE

NVD-CWE-noinfo

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2021-43040",
  "cveTags": [],
  "metrics": {
    "cvssMetricV2": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "version": "2.0",
          "baseScore": 6.5,
          "accessVector": "NETWORK",
          "vectorString": "AV:N/AC:L/Au:S/C:P/I:P/A:P",
          "authentication": "SINGLE",
          "integrityImpact": "PARTIAL",
          "accessComplexity": "LOW",
          "availabilityImpact": "PARTIAL",
          "confidentialityImpact": "PARTIAL"
        },
        "acInsufInfo": false,
        "impactScore": 6.4,
        "baseSeverity": "MEDIUM",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 8,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 8.8,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 2.8
      }
    ]
  },
  "affected": [
    {
      "source": "cve@mitre.org",
      "affectedData": [
        {
          "vendor": "n/a",
          "product": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ]
    }
  ],
  "published": "2021-12-06T04:15:07.457",
  "references": [
    {
      "url": "https://helpdesk.kaseya.com/hc/en-gb/articles/4412762258961",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "cve@mitre.org"
    },
    {
      "url": "https://www.cyberonesecurity.com/blog/exploiting-kaseya-unitrends-backup-appliance-part-1",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "source": "cve@mitre.org"
    },
    {
      "url": "https://www.cyberonesecurity.com/blog/exploiting-kaseya-unitrends-backup-appliance-part-2",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "source": "cve@mitre.org"
    },
    {
      "url": "https://helpdesk.kaseya.com/hc/en-gb/articles/4412762258961",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://www.cyberonesecurity.com/blog/exploiting-kaseya-unitrends-backup-appliance-part-1",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://www.cyberonesecurity.com/blog/exploiting-kaseya-unitrends-backup-appliance-part-2",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "An issue was discovered in Kaseya Unitrends Backup Appliance before 10.5.5. The privileged vaultServer could be leveraged to create arbitrary writable files, leading to privilege escalation."
    },
    {
      "lang": "es",
      "value": "Se ha detectado un problema en Kaseya Unitrends Backup Appliance versiones anteriores a 10.5.5. El vaultServer privilegiado podría ser aprovechado para crear archivos arbitrarios con capacidad de escritura, conllevando a una escalada de privilegios"
    }
  ],
  "lastModified": "2026-06-17T04:10:25.130",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:kaseya:unitrends_backup:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "0AB6E40C-C11C-4C88-97AA-28D0457182BF",
              "versionEndExcluding": "10.5.5",
              "versionStartIncluding": "10.0"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "cve@mitre.org"
}