Yesterday Jacob Appelbaum discovered an input sanitation bug in OnionShare 0.3. It is now fixed, and you should upgrade to the latest version before using it again. You can download the latest version from https://onionshare.org/.
more here.............https://micahflee.com/2014/07/security-advisory-upgrade-to-onionshare-0-4-immediately/
more here.............https://micahflee.com/2014/07/security-advisory-upgrade-to-onionshare-0-4-immediately/