The Net::EasyTCP package before 0.15 for Perl always uses Perl's builtin rand(), which is not a strong random number generator, for cryptographic keys.
https://metacpan.org/release/MNAGUIB/EasyTCP-0.26/changes
https://metacpan.org/release/MNAGUIB/EasyTCP-0.15/view/EasyTCP.pm
https://github.com/briandfoy/cpan-security-advisory/issues/184