CVE Vulnerabilities

CVE-2018-14715

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

Published: Aug 03, 2018 | Modified: Oct 02, 2018
CVSS 3.x
7.5
HIGH
Source:
NVD
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS 2.x
5 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:N
RedHat/V2
RedHat/V3
Ubuntu

The endCoinFlip function and throwSlammer function of the smart contract implementations for Cryptogs, an Ethereum game, generate random numbers with an old block’s hash. Therefore, attackers can predict the random number and always win the game.

Weakness

The product uses a Pseudo-Random Number Generator (PRNG) in a security context, but the PRNG’s algorithm is not cryptographically strong.

Affected Software

Name Vendor Start Version End Version
Cryptogs Cryptogs - -

Extended Description

When a non-cryptographic PRNG is used in a cryptographic context, it can expose the cryptography to certain types of attacks. Often a pseudo-random number generator (PRNG) is not designed for cryptography. Sometimes a mediocre source of randomness is sufficient or preferable for algorithms that use random numbers. Weak generators generally take less processing power and/or do not use the precious, finite, entropy sources on a system. While such PRNGs might have very useful features, these same features could be used to break the cryptography.

Potential Mitigations

References