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Fencer Intel
high 7.5

CVE-2018-17877 json

A lottery smart contract implementation for Greedy 599, an Ethereum gambling game, generates a random value that is predictable via an exte…

published 2018-10-23 8 y ago modified 2026-06-17 4 mo ago also EUVD-2018-9618

cvss
7.5
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.6%
EPSS 1.6% chance of exploitation in 30 days, percentile 76%
public exploits
0
none known

Summary

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.

Exploit prediction

1.64% chance of exploitation in the next 30 days, higher than 76% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/TEAM-C4B/CVE-LIST/tree/master/CVE-2018-17877 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.0 7.5 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:P/I:N/A:N

Classification

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

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.