The make_temporary_filename function in perltidy 20120701-1 and earlier allows local users to obtain sensitive information or write to arbitrary files via a symlink attack, related to use of the tmpnam function.

perltidy through 20160302, as used by perlcritic, check-all-the-things, and other software, relies on the current working directory for certain output files and does not have a symlink-attack protection mechanism, which allows local users to overwrite arbitrary files by creating a symlink, as demonstrated by creating a perltidy.ERR symlink that the victim cannot delete.