This can be avoided using the Safe module. Build the compartment to evaluate the Perl-code configuration using

$compartment = new Safe;
$compartment->permit_only(qw(:base_core :base_mem)); # very restrictiv
+e
$result = $compartment->reval($unsafe_code);
[download]

and the evaluated code will not be able to do anything than build data structures. (See perldoc Opcode for a list of tags.)

Makeshifts last the longest.