Multiple directory traversal vulnerabilities in Private Messaging System (PMS) 1.2.3 and earlier for PunBB allow remote attackers to include and execute arbitrary files via a .. (dot dot) in the pun_user[language] parameter to (1) functions_navlinks.php, (2) header_new_messages.php, (3) profile_send.php, and (4) viewtopic_PM-link.php in include/pms/.
Improper Limitation of a Pathname to a Restricted Directory The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.