CVE-2020-8912

{
  "id": "CVE-2020-8912",
  "cveTags": [],
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    "cvssMetricV2": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
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          "baseScore": 2.1,
          "accessVector": "LOCAL",
          "vectorString": "AV:L/AC:L/Au:N/C:P/I:N/A:N",
          "authentication": "NONE",
          "integrityImpact": "NONE",
          "accessComplexity": "LOW",
          "availabilityImpact": "NONE",
          "confidentialityImpact": "PARTIAL"
        },
        "acInsufInfo": false,
        "impactScore": 2.9,
        "baseSeverity": "LOW",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 3.9,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "cve-coordination@google.com",
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          "scope": "UNCHANGED",
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          "baseScore": 2.5,
          "attackVector": "LOCAL",
          "baseSeverity": "LOW",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "availabilityImpact": "NONE",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "LOW"
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        "impactScore": 1.4,
        "exploitabilityScore": 1
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          "attackVector": "LOCAL",
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          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "availabilityImpact": "NONE",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "LOW"
        },
        "impactScore": 1.4,
        "exploitabilityScore": 1
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  },
  "affected": [
    {
      "source": "cve-coordination@google.com",
      "affectedData": [
        {
          "vendor": "Google LLC",
          "product": "AWS S3 Crypto SDK for GoLang",
          "versions": [
            {
              "status": "affected",
              "version": "stable",
              "versionType": "custom",
              "lessThanOrEqual": "V1"
            }
          ]
        }
      ]
    }
  ],
  "published": "2020-08-11T20:15:13.323",
  "references": [
    {
      "url": "https://aws.amazon.com/blogs/developer/updates-to-the-amazon-s3-encryption-client/?s=09",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "cve-coordination@google.com"
    },
    {
      "url": "https://github.com/google/security-research/security/advisories/GHSA-7f33-f4f5-xwgw",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "source": "cve-coordination@google.com"
    },
    {
      "url": "https://aws.amazon.com/blogs/developer/updates-to-the-amazon-s3-encryption-client/?s=09",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://github.com/google/security-research/security/advisories/GHSA-7f33-f4f5-xwgw",
      "tags": [
        "Exploit",
        "Third Party Advisory"
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      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "cve-coordination@google.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-327"
        }
      ]
    },
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-327"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "A vulnerability in the in-band key negotiation exists in the AWS S3 Crypto SDK for GoLang versions prior to V2. An attacker with write access to the targeted bucket can change the encryption algorithm of an object in the bucket, which can then allow them to change AES-GCM to AES-CTR. Using this in combination with a decryption oracle can reveal the authentication key used by AES-GCM as decrypting the GMAC tag leaves the authentication key recoverable as an algebraic equation. It is recommended to update your SDK to V2 or later, and re-encrypt your files."
    },
    {
      "lang": "es",
      "value": "Se presenta una vulnerabilidad en la negociación de claves in-band en AWS S3 Crypto SDK para GoLang versiones anteriores a la versión V2. Un atacante con acceso de escritura al depósito de destino puede cambiar el algoritmo de cifrado de un objeto en el depósito, lo que luego puede permitirle cambiar AES-GCM a AES-CTR. El uso de esto en combinación con un oráculo de descifrado puede revelar la clave de autenticación usada por AES-GCM ya que descifrar la etiqueta GMAC deja la clave de autenticación recuperable como una ecuación algebraica. Se recomienda actualizar su SDK a la versión V2 o posterior y volver a cifrar sus archivos"
    }
  ],
  "lastModified": "2026-06-17T03:27:10.440",
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}