{
  "id": "CVE-2018-17071",
  "sourceIdentifier": "cve@mitre.org",
  "published": "2018-09-18T21:29:03.807",
  "lastModified": "2018-12-10T14:53:01.917",
  "vulnStatus": "Analyzed",
  "descriptions": [
    {
      "lang": "en",
      "value": "The fallback function of a simple lottery smart contract implementation for Lucky9io, an Ethereum gambling game, generates a random value with the publicly readable variable entry_number. This variable is private, yet it is readable by eth.getStorageAt function. Also, attackers can purchase a ticket at a low price by directly calling the fallback function with small msg.value, because the developer set the currency unit incorrectly. Therefore, it allows attackers to always win and get rewards."
    },
    {
      "lang": "es",
      "value": "La funci\u00f3n fallback de una simple implementaci\u00f3n de contrato inteligente de loter\u00eda para Lucky9io, un juego de apuestas de Ethereum, genera un valor aleatorio con la variable legible p\u00fablicamente entry_number. Este valor es privado, aunque puede ser le\u00eddo por la funci\u00f3n eth.getStorageAt. Adem\u00e1s, los atacantes pueden comprar un ticket a bajo precio llamando directamente a la funci\u00f3n fallback con un msg.value peque\u00f1o. Esto se debe a que el desarrollador ha establecido la divisa incorrectamente.  Por lo tanto, permite que los atacantes ganen siempre y obtengan recompensas."
    }
  ],
  "metrics": {
    "cvssMetricV30": [
      {
        "source": "nvd@nist.gov",
        "type": "Primary",
        "cvssData": {
          "version": "3.0",
          "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "availabilityImpact": "NONE",
          "baseScore": 7.5,
          "baseSeverity": "HIGH"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6
      }
    ],
    "cvssMetricV2": [
      {
        "source": "nvd@nist.gov",
        "type": "Primary",
        "cvssData": {
          "version": "2.0",
          "vectorString": "AV:N/AC:L/Au:N/C:P/I:N/A:N",
          "accessVector": "NETWORK",
          "accessComplexity": "LOW",
          "authentication": "NONE",
          "confidentialityImpact": "PARTIAL",
          "integrityImpact": "NONE",
          "availabilityImpact": "NONE",
          "baseScore": 5.0
        },
        "baseSeverity": "MEDIUM",
        "exploitabilityScore": 10.0,
        "impactScore": 2.9,
        "acInsufInfo": false,
        "obtainAllPrivilege": false,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
    ]
  },
  "weaknesses": [
    {
      "source": "nvd@nist.gov",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-338"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:lucky9:lucky9io:-:*:*:*:*:*:*:*",
              "matchCriteriaId": "A90B2110-2E27-4E5F-B298-6A62FE97F3E1"
            }
          ]
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/TEAM-C4B/CVE-LIST/tree/master/CVE-2018-17071",
      "source": "cve@mitre.org",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ]
    }
  ]
}