« Volver al listado

CVE-2026-27750

Estado: ModificadaAlta (7)—

Avira Internet Security contains a time-of-check time-of-use (TOCTOU) vulnerability in the Optimizer component. A privileged service running as SYSTEM identifies directories for cleanup during a scan phase and subsequently deletes them during a separate cleanup phase without revalidating the target path. A local attacker can replace a previously scanned directory with a junction or reparse point before deletion occurs, causing the privileged process to delete an unintended system location. This may result in deletion of protected files or directories and can lead to local privilege escalation, denial of service, or system integrity compromise depending on the affected target.

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.

TOCTOU en servicio SYSTEM con acceso local y PR:L permite escalada de privilegios. Reemplazo de ruta mediante junction/reparse point causa eliminación maliciosa de archivos del sistema (integridad) y potencial DoS.

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

Threat Intelligence ProgramRestrict File and Directory PermissionsRemote Data StorageFilter Network TrafficExecution PreventionEncrypt Sensitive Information

Tecnologías afectadas (1)

Avira — Internet Security

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2026-27750",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-27750",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-03-06T18:17:35.645224Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "security@nortonlifelock.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.8,
          "attackVector": "LOCAL",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:L/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": 1.8
      },
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7,
          "attackVector": "LOCAL",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 1
      }
    ]
  },
  "affected": [
    {
      "source": "security@nortonlifelock.com",
      "affectedData": [
        {
          "vendor": "Gen Digital Inc.",
          "product": "Avira Internet Security",
          "versions": [
            {
              "status": "affected",
              "version": "0",
              "versionType": "semver",
              "lessThanOrEqual": "1.1.109.1990"
            },
            {
              "status": "unaffected",
              "version": "1.1.114.3113",
              "versionType": "semver"
            }
          ],
          "platforms": [
            "Windows"
          ],
          "defaultStatus": "unaffected"
        }
      ]
    }
  ],
  "published": "2026-03-05T15:16:12.153",
  "references": [
    {
      "url": "https://support.avira.com/hc/en-us/articles/360010656158-Current-Avira-versions",
      "tags": [
        "Release Notes"
      ],
      "source": "security@nortonlifelock.com"
    },
    {
      "url": "https://www.avira.com/en/internet-security",
      "tags": [
        "Product"
      ],
      "source": "security@nortonlifelock.com"
    },
    {
      "url": "https://www.gendigital.com/us/en/contact-us/security-advisories/",
      "source": "security@nortonlifelock.com"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "security@nortonlifelock.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-367"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Avira Internet Security contains a time-of-check time-of-use (TOCTOU) vulnerability in the Optimizer component. A privileged service running as SYSTEM identifies directories for cleanup during a scan phase and subsequently deletes them during a separate cleanup phase without revalidating the target path. A local attacker can replace a previously scanned directory with a junction or reparse point before deletion occurs, causing the privileged process to delete an unintended system location. This may result in deletion of protected files or directories and can lead to local privilege escalation, denial of service, or system integrity compromise depending on the affected target."
    },
    {
      "lang": "es",
      "value": "Avira Internet Security contiene una vulnerabilidad de tiempo de comprobación y tiempo de uso (TOCTOU) en el componente Optimizer. Un servicio con privilegios que se ejecuta como SYSTEM identifica los directorios que deben limpiarse durante una fase de análisis y, posteriormente, los elimina durante una fase de limpieza independiente sin volver a validar la ruta de destino. Un atacante local puede sustituir un directorio escaneado previamente por un punto de unión o de reanálisis antes de que se produzca la eliminación, lo que provoca que el proceso con privilegios elimine una ubicación del sistema no deseada. Esto puede dar lugar a la eliminación de archivos o directorios protegidos y puede provocar una escalada de privilegios locales, una denegación de servicio o un compromiso de la integridad del sistema, dependiendo del objetivo afectado."
    }
  ],
  "lastModified": "2026-06-17T10:27:37.850",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:avira:internet_security:*:*:*:*:*:windows:*:*",
              "vulnerable": true,
              "matchCriteriaId": "DFB6EFB7-8777-4A9B-9A00-2FBEE12A7090",
              "versionEndExcluding": "1.1.114.3113"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "security@nortonlifelock.com"
}