VULNERABILITY INTELLIGENCE

CVE-2018-17877

CVSS score7.5 HIGH
EPSS probability1.64%
CISA KEVNot currently listed
Published2018-10-23
Last modified2026-06-17
CVSS vectorCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

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.

Weakness classification

  • CWE-338: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

Primary references