The SAML identifier generated within SAML2Utils.java was found to make use of the apache commons-lang3 RandomStringUtils class which makes them predictable due to RandomStringUtils PRNGs algorithm not being cryptographically strong. This issue only affects the 3.X release of pac4j-saml.
The product uses a Pseudo-Random Number Generator (PRNG) in a security context, but the PRNG’s algorithm is not cryptographically strong.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Pac4j | Pac4j | 3.0.0 (including) | 3.8.2 (including) |
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.