« Volver al listado

CVE-2021-22538

Estado: ModificadaAlta (8.8)—

A privilege escalation vulnerability impacting the Google Exposure Notification Verification Server (versions prior to 0.23.1), allows an attacker who (1) has UserWrite permissions and (2) is using a carefully crafted request or malicious proxy, to create another user with higher privileges than their own. This occurs due to insufficient checks on the allowed set of permissions. The new user creation event would be captured in the Event Log.

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)

Google — Exposure Notifications Verification Server

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2021-22538",
  "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": "Secondary",
        "source": "cve-coordination@google.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 6.3,
          "attackVector": "NETWORK",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L",
          "integrityImpact": "LOW",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "LOW",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "LOW"
        },
        "impactScore": 3.4,
        "exploitabilityScore": 2.8
      },
      {
        "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-coordination@google.com",
      "affectedData": [
        {
          "vendor": "Google LLC",
          "product": "Exposure Notifications Verification Server",
          "versions": [
            {
              "status": "affected",
              "version": "stable",
              "versionType": "custom",
              "lessThanOrEqual": "0.23.0"
            }
          ],
          "platforms": [
            "all"
          ]
        }
      ]
    }
  ],
  "published": "2021-03-31T21:15:16.057",
  "references": [
    {
      "url": "https://github.com/google/exposure-notifications-verification-server/commit/eb8cf40b12dbe79304f1133c06fb73419383cd95",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "source": "cve-coordination@google.com"
    },
    {
      "url": "https://github.com/google/exposure-notifications-verification-server/releases/tag/v0.23.1",
      "tags": [
        "Release Notes",
        "Third Party Advisory"
      ],
      "source": "cve-coordination@google.com"
    },
    {
      "url": "https://github.com/google/exposure-notifications-verification-server/releases/tag/v0.24.0",
      "tags": [
        "Release Notes",
        "Third Party Advisory"
      ],
      "source": "cve-coordination@google.com"
    },
    {
      "url": "https://github.com/google/exposure-notifications-verification-server/security/advisories/GHSA-5v95-v8c8-3rh6",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "cve-coordination@google.com"
    },
    {
      "url": "https://github.com/google/exposure-notifications-verification-server/commit/eb8cf40b12dbe79304f1133c06fb73419383cd95",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://github.com/google/exposure-notifications-verification-server/releases/tag/v0.23.1",
      "tags": [
        "Release Notes",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://github.com/google/exposure-notifications-verification-server/releases/tag/v0.24.0",
      "tags": [
        "Release Notes",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://github.com/google/exposure-notifications-verification-server/security/advisories/GHSA-5v95-v8c8-3rh6",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "cve-coordination@google.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-20"
        }
      ]
    },
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-276"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "A privilege escalation vulnerability impacting the Google Exposure Notification Verification Server (versions prior to 0.23.1), allows an attacker who (1) has UserWrite permissions and (2) is using a carefully crafted request or malicious proxy, to create another user with higher privileges than their own. This occurs due to insufficient checks on the allowed set of permissions. The new user creation event would be captured in the Event Log."
    },
    {
      "lang": "es",
      "value": "Una vulnerabilidad de escalada de privilegios que afecta al Google Exposure Notification Verification Server (versiones anteriores a 0.23.1), permite a un atacante que (1) tenga permisos de UserWrite y (2) esté usando una petición cuidadosamente diseñada o un proxy malicioso, crear otro usuario con un nivel de privilegios mayores que los suyos. Esto se presenta debido a controles insuficientes sobre el conjunto permitido de permisos. El evento de creación de nuevo usuario se capturaría en el Registro de Eventos."
    }
  ],
  "lastModified": "2026-06-17T03:37:24.067",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:google:exposure_notifications_verification_server:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "4AB50BC0-EC62-473B-8550-917FB077D093",
              "versionEndExcluding": "0.23.1"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "cve-coordination@google.com"
}