Versions of this module prior to 2.17 were incorrectly
using 8 byte IVs when generating the old-style RandomIV style header
(as opposed to the new-style random salt header). This affects data
encrypted using the Rijndael algorithm, which has a 16 byte blocksize,
and is a significant security issue.
The bug has been corrected in versions 2.17 and higher by making it
impossible to use 16-byte block ciphers with RandomIV headers. You may
still read legacy encrypted data by explicitly passing the
-insecure_legacy_decrypt option to Crypt::CBC->new().
This is Crypt::CBC, a Perl-only implementation of the cryptographic
cipher block chaining mode (CBC). In combination with a block cipher
such as Crypt::DES or Crypt::IDEA, you can encrypt and decrypt messages
of arbitrarily long length.