Small Seed Space in PRNG
A Pseudo-Random Number Generator (PRNG) uses a relatively small seed space, which makes it more susceptible to brute force attacks.
PRNGs are entirely deterministic once seeded, so it should be extremely difficult to guess the seed. If an attacker can collect the outputs of a PRNG and then brute force the seed by trying every possibility to see which seed matches the observed output, then the attacker will know the output of any subsequent calls to the PRNG. A small seed space implies that the attacker will have far fewer possible values to try to exhaust all possibilities.
The following examples help to illustrate the nature of this weakness and describe methods or techniques which can be used to mitigate the risk.
Note that the examples here are by no means exhaustive and any given weakness may have many subtle varieties, each of which may require different detection methods or runtime controls.
This code grabs some random bytes and uses them for a seed in a PRNG, in order to generate a new cryptographic key.
Since only 2 bytes is used as a seed, an attacker will only need to guess 2^16 (65,536) values before being able to replicate the state of the PRNG.
Weaknesses in this category are related to the design and architecture of data confidentiality in a system. Frequently these deal with the use of encryption libraries....
This category identifies Software Fault Patterns (SFPs) within the Predictability cluster.
This view (slice) covers all the elements in CWE.
CWE entries in this view have maintenance notes. Maintenance notes are an indicator that an entry might change significantly in future versions. This view was created...
CWE identifiers in this view are weaknesses that do not have associated Software Fault Patterns (SFPs), as covered by the CWE-888 view. As such, they represent gaps in...