/usr/share/perl5/CGI/Session/ is in libcgi-session-perl 4.48-1+deb8u1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/perl5/CGI/Session/Driver/
/usr/share/perl5/CGI/Session/Driver.pm
/usr/share/perl5/CGI/Session/Driver/DBI.pm
/usr/share/perl5/CGI/Session/Driver/db_file.pm
/usr/share/perl5/CGI/Session/Driver/file.pm
/usr/share/perl5/CGI/Session/Driver/mysql.pm
/usr/share/perl5/CGI/Session/Driver/postgresql.pm
/usr/share/perl5/CGI/Session/Driver/sqlite.pm
/usr/share/perl5/CGI/Session/ErrorHandler.pm
/usr/share/perl5/CGI/Session/ID/
/usr/share/perl5/CGI/Session/ID/incr.pm
/usr/share/perl5/CGI/Session/ID/md5.pm
/usr/share/perl5/CGI/Session/ID/static.pm
/usr/share/perl5/CGI/Session/Serialize/
/usr/share/perl5/CGI/Session/Serialize/default.pm
/usr/share/perl5/CGI/Session/Serialize/freezethaw.pm
/usr/share/perl5/CGI/Session/Serialize/storable.pm
/usr/share/perl5/CGI/Session/Test/
/usr/share/perl5/CGI/Session/Test/Default.pm
/usr/share/perl5/CGI/Session/Tutorial.pm