Data::Entropy for Perl 0.007 and earlier use the rand() function as the default source of entropy, which is not cryptographically secure, for cryptographic functions.
https://perldoc.perl.org/functions/rand
https://metacpan.org/release/ZEFRAM/Data-Entropy-0.007/source/lib/Data/Entropy.pm#L80
https://lists.debian.org/debian-lts-announce/2025/03/msg00026.html