FKIE_CVE-2020-8918

Vulnerability from fkie_nvd - Published: 2020-08-11 19:15 - Updated: 2026-06-17 03:27
Severity
6.3 (Medium) - CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
7.1 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Summary
An improperly initialized 'migrationAuth' value in Google's go-tpm TPM1.2 library versions prior to 0.3.0 can lead an eavesdropping attacker to discover the auth value for a key created with CreateWrapKey. An attacker listening in on the channel can collect both 'encUsageAuth' and 'encMigrationAuth', and then can calculate 'usageAuth ^ encMigrationAuth' as the 'migrationAuth' can be guessed for all keys created with CreateWrapKey. TPM2.0 is not impacted by this. We recommend updating your library to 0.3.0 or later, or, if you cannot update, to call CreateWrapKey with a random 20-byte value for 'migrationAuth'.
References
cve-coordination@google.comhttps://github.com/google/go-tpm/security/advisories/GHSA-5x29-3hr9-6wpwExploit, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://github.com/google/go-tpm/security/advisories/GHSA-5x29-3hr9-6wpwExploit, Third Party Advisory
Impacted products
Vendor Product Version
google go-tpm *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "google/go-tpm library",
          "vendor": "Google LLC",
          "versions": [
            {
              "lessThan": "0.3.0",
              "status": "affected",
              "version": "stable",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "cve-coordination@google.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:google:go-tpm:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "4C01295C-C049-40D7-AB0A-58BAEEC81283",
              "versionEndExcluding": "0.3.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "An improperly initialized \u0027migrationAuth\u0027 value in Google\u0027s go-tpm TPM1.2 library versions prior to 0.3.0 can lead an eavesdropping attacker to discover the auth value for a key created with CreateWrapKey. An attacker listening in on the channel can collect both \u0027encUsageAuth\u0027 and \u0027encMigrationAuth\u0027, and then can calculate \u0027usageAuth ^ encMigrationAuth\u0027 as the \u0027migrationAuth\u0027 can be guessed for all keys created with CreateWrapKey. TPM2.0 is not impacted by this. We recommend updating your library to 0.3.0 or later, or, if you cannot update, to call CreateWrapKey with a random 20-byte value for \u0027migrationAuth\u0027."
    },
    {
      "lang": "es",
      "value": "Un valor de \"migrationAuth\" inicializado inapropiadamente en la biblioteca go-tpm TPM1.2 de Google versiones anteriores a 0.3.0, puede conllevar a un atacante que esp\u00eda a detectar el valor de autenticaci\u00f3n de una clave creada con CreateWrapKey. Un atacante que escucha en el canal puede recopilar \"encUsageAuth\" y \"encMigrationAuth\", y luego puede calcular \"useAuth ^ encMigrationAuth\" ya que se puede adivinar \"migrationAuth\" para todas las claves creadas con CreateWrapKey. TPM2.0 no est\u00e1 afectado por esto. Recomendamos actualizar su biblioteca a la versi\u00f3n 0.3.0 o posterior o, si no puede actualizar, llamar a CreateWrapKey con un valor aleatorio de 20 bytes para \"migrationAuth\""
    }
  ],
  "id": "CVE-2020-8918",
  "lastModified": "2026-06-17T03:27:10.777",
  "metrics": {
    "cvssMetricV2": [
      {
        "acInsufInfo": false,
        "baseSeverity": "LOW",
        "cvssData": {
          "accessComplexity": "LOW",
          "accessVector": "LOCAL",
          "authentication": "NONE",
          "availabilityImpact": "NONE",
          "baseScore": 3.6,
          "confidentialityImpact": "PARTIAL",
          "integrityImpact": "PARTIAL",
          "vectorString": "AV:L/AC:L/Au:N/C:P/I:P/A:N",
          "version": "2.0"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 4.9,
        "obtainAllPrivilege": false,
        "obtainOtherPrivilege": false,
        "obtainUserPrivilege": false,
        "source": "nvd@nist.gov",
        "type": "Primary",
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "LOCAL",
          "availabilityImpact": "NONE",
          "baseScore": 6.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 1.0,
        "impactScore": 5.2,
        "source": "cve-coordination@google.com",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "NONE",
          "baseScore": 7.1,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.2,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2020-08-11T19:15:17.547",
  "references": [
    {
      "source": "cve-coordination@google.com",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "url": "https://github.com/google/go-tpm/security/advisories/GHSA-5x29-3hr9-6wpw"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "url": "https://github.com/google/go-tpm/security/advisories/GHSA-5x29-3hr9-6wpw"
    }
  ],
  "sourceIdentifier": "cve-coordination@google.com",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-665"
        }
      ],
      "source": "cve-coordination@google.com",
      "type": "Secondary"
    },
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-665"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



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