« Volver al listado

CVE-2021-27241

Estado: ModificadaMedia (6.1)—

This vulnerability allows local attackers to delete arbitrary directories on affected installations of Avast Premium Security 20.8.2429 (Build 20.8.5653.561). An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the AvastSvc.exe module. By creating a directory junction, an attacker can abuse the service to delete a directory. An attacker can leverage this vulnerability to create a denial-of-service condition on the system. Was ZDI-CAN-12082.

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)

Avast — Premium Security

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2021-27241",
  "cveTags": [],
  "metrics": {
    "cvssMetricV2": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "version": "2.0",
          "baseScore": 3.6,
          "accessVector": "LOCAL",
          "vectorString": "AV:L/AC:L/Au:N/C:N/I:P/A:P",
          "authentication": "NONE",
          "integrityImpact": "PARTIAL",
          "accessComplexity": "LOW",
          "availabilityImpact": "PARTIAL",
          "confidentialityImpact": "NONE"
        },
        "acInsufInfo": false,
        "impactScore": 4.9,
        "baseSeverity": "LOW",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 3.9,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV30": [
      {
        "type": "Secondary",
        "source": "zdi-disclosures@trendmicro.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.0",
          "baseScore": 6.1,
          "attackVector": "LOCAL",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H",
          "integrityImpact": "LOW",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 4.2,
        "exploitabilityScore": 1.8
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 6.1,
          "attackVector": "LOCAL",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H",
          "integrityImpact": "LOW",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 4.2,
        "exploitabilityScore": 1.8
      }
    ]
  },
  "affected": [
    {
      "source": "zdi-disclosures@trendmicro.com",
      "affectedData": [
        {
          "vendor": "Avast",
          "product": "Premium Security",
          "versions": [
            {
              "status": "affected",
              "version": "20.8.2429 (Build 20.8.5653.561)"
            }
          ]
        }
      ]
    }
  ],
  "published": "2021-03-29T21:15:12.593",
  "references": [
    {
      "url": "https://www.zerodayinitiative.com/advisories/ZDI-21-208/",
      "tags": [
        "Third Party Advisory",
        "VDB Entry"
      ],
      "source": "zdi-disclosures@trendmicro.com"
    },
    {
      "url": "https://www.zerodayinitiative.com/advisories/ZDI-21-208/",
      "tags": [
        "Third Party Advisory",
        "VDB Entry"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "zdi-disclosures@trendmicro.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-59"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "This vulnerability allows local attackers to delete arbitrary directories on affected installations of Avast Premium Security 20.8.2429 (Build 20.8.5653.561). An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the AvastSvc.exe module. By creating a directory junction, an attacker can abuse the service to delete a directory. An attacker can leverage this vulnerability to create a denial-of-service condition on the system. Was ZDI-CAN-12082."
    },
    {
      "lang": "es",
      "value": "Esta vulnerabilidad permite a atacantes locales eliminar directorios arbitrarios en las instalaciones afectadas de Avast Premium Security versión 20.8.2429 (Build 20.8.5653.561). Un atacante primero debe obtener la capacidad de ejecutar código poco privilegiado en el sistema de destino para explotar esta vulnerabilidad. El fallo específico se presenta dentro del módulo AvastSvc.exe. Al crear una unión de directorio, un atacante puede abusar del servicio para eliminar un directorio. Un atacante puede aprovechar esta vulnerabilidad para crear una condición de denegación de servicio en el sistema. Era ZDI-CAN-12082"
    }
  ],
  "lastModified": "2026-06-17T03:44:31.850",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:avast:premium_security:20.8.2429:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "2686D810-4654-4FF3-A785-A2B43139967E"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "zdi-disclosures@trendmicro.com"
}