mail2sms.sh in smsclient 2.0.8z allows local users to overwrite arbitrary files via a symlink attack on a (1) /tmp/header.##### or (2) /tmp/body.##### temporary file, or append data to arbitrary files via a symlink attack on the (3) /tmp/sms.log temporary file.
Improper Link Resolution Before File Access The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.