CWE-332Insufficient Entropy in PRNG

Description

Common consequences· 2

• Availability — DoS: Crash, Exit, or Restart
  If a pseudo-random number generator is using a limited entropy source which runs out (if the generator fails closed), the program may pause or crash.
• Access Control / Other — Bypass Protection Mechanism, Other
  If a PRNG is using a limited entropy source which runs out, and the generator fails open, the generator could produce predictable random numbers. Potentially a weak source of random numbers could weaken the encryption method used for authentication of users.

Potential mitigations· 3

• [Architecture and Design, Requirements]Use products or modules that conform to FIPS 140-2 [REF-267] to avoid obvious entropy problems. Consult FIPS 140-2 Annex C ("Approved Random Number Generators").
• [Implementation]Consider a PRNG that re-seeds itself as needed from high-quality pseudo-random output, such as hardware devices.
• [Architecture and Design]When deciding which PRNG to use, look at its sources of entropy. Depending on what your security needs are, you may need to use a random number generator that always uses strong random data -- i.e., a random number generator that attempts to be strong but will fail in a weak way or will always provide some middle ground of protection through techniques like re-seeding. Generally, something that always provides a predictable amount of strength is preferable.

Related by meaning· 6

Nearest entities by semantic similarity across the cs-graph corpus.