newsgrab -- insecure file and directory creation

The newsgrab script uses insecure permissions during the
creation of the local output directory and downloaded files.
After a file is created, permissions on it are set using the mode
value of the newsgroup posting. This can potentially be a problem
when the mode is not restrictive enough. In addition, the output
directory is created with world writable permissions allowing other
users to drop symlinks or other files at that location.