WebService::Xero 0.11 and earlier for Perl uses the rand() function as the default source of entropy, which is not cryptographically secure, for cryptographic functions.
Specifically WebService::Xero uses the Data::Random library which specifically states that it is Useful mostly for test programs. Data::Random uses the rand() function.
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 |
|---|---|---|---|
| Webservice::xero | Localshop | * | 0.11 (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.