CGI::Session 4.03-1 allows local users to overwrite arbitrary files via a symlink attack on temporary files used by (1) Driver::File, (2) Driver::db_file, and possibly (3) Driver::sqlite.

CGI::Session 4.03-1 does not set proper permissions on temporary files created in (1) Driver::File and (2) Driver::db_file, which allows local users to obtain privileged information, such as session keys, by viewing the files.