{"id":"CVE-2018-17877","url":"https://www.cyber-defence.io/tools/cve/CVE-2018-17877","generatedAt":"2026-10-29T01:51:02.533Z","title":"The developer used the extcodesize() function to prevent a malicious contract from being called, but the attacker can bypass it by writing the core code in the constructor of their exploit code.","description":"A lottery smart contract implementation for Greedy 599, an Ethereum gambling game, generates a random value that is predictable via an external contract call. The developer used the extcodesize() function to prevent a malicious contract from being called, but the attacker can bypass it by writing the core code in the constructor of their exploit code. Therefore, it allows attackers to always win and get rewards.","published":"2018-10-23T21:30:54.000Z","lastModified":"2026-06-17T01:46:27.000Z","status":"Modified","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.0","score":7.5,"severity":"HIGH","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},"cwe":["CWE-338"],"affected":["greedy599/greedy 599"],"epss":{"score":0.01637,"percentile":0.76205,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (1.64%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/TEAM-C4B/CVE-LIST/tree/master/CVE-2018-17877","tags":["Exploit","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/TEAM-C4B/CVE-LIST/tree/master/CVE-2018-17877","tags":["Exploit","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2018-17877","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}