Net::NSCA::Client versions through 0.009002 for Perl uses a poor random number generator.
Version v0.003 switched to use Data::Rand::Obscure instead of Crypt::Random for generation of a random initialisation vectors.
Data::Rand::Obscure uses Perl's built-in rand() function, which is not suitable for cryptographic functions.
Apply a manual patch or migrate to a different solution