What is CVE-2018-17071?

CVE-2018-17071 is a high-severity vulnerability in Lucky9 Lucky9io, classified under Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG). CVSS score: 7.5/10. Published 2018-09-18.

How severe is CVE-2018-17071?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Lucky9 Lucky9io

CVE-2018-17071

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.

EPSS: 0.012 (65.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

Affected products

Lucky9 Lucky9io
N/a — versions n/a

Weakness classification (CWE)

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

References

cve@mitre.org (Exploit, Third Party Advisory, x_refsource_MISC)

Frequently asked questions

What is CVE-2018-17071?: CVE-2018-17071 is a high-severity vulnerability in Lucky9 Lucky9io, classified under Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG). CVSS score: 7.5/10. Published 2018-09-18.
How severe is CVE-2018-17071?: High severity. CVSS v3 base score is 7.5 out of 10.