CWE-338

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

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

Status
draft
Abstraction
base
Likelihood
medium

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.

Common Consequences

access control
Impacts
bypass protection mechanism

Detection Methods

automated static analysis

Potential Mitigations

Phases:
implementation
Descriptions:
• Use functions or hardware which use a hardware-based random number generation for all crypto. This is the recommended solution. Use CyptGenRandom on Windows, or hw_rand() on Linux.