An issue was discovered in the DBI module before 1.632 for Perl. DBD::File drivers can open files from folders other than those specifically passed via the f_dir attribute.
https://usn.ubuntu.com/4509-1/
https://rt.cpan.org/Public/Bug/Display.html?id=99508
https://metacpan.org/pod/distribution/DBI/Changes#Changes-in-DBI-1.632-9th-Nov-2014
https://github.com/perl5-dbi/dbi/commit/caedc0d7d602f5b2ae5efc1b00f39efeafb7b05a