PHP remote file inclusion vulnerability in lib/pcltar.lib.php (aka pcltar.php) in the PclTar module 1.3 and 1.3.1 for Vincent Blavet PhpConcept Library, as used in multiple products including (1) Joomla! 1.5.0 Beta, (2) N/X Web Content Management System (WCMS) 4.5, (3) CJG EXPLORER PRO 3.3, and (4) phpSiteBackup 0.1, allows remote attackers to execute arbitrary PHP code via a URL in the g_pcltar_lib_dir parameter.