cloner.functions.php in the XCloner plugin 3.1.1 for WordPress and 3.5.1 for Joomla! allows remote administrators to execute arbitrary code via shell metacharacters in the (1) file name when creating a backup or vectors related to the (2) $_CONFIG[tarpath], (3) $exclude, (4) $_CONFIG['tarcompress'], (5) $_CONFIG['filename'], (6) $_CONFIG['exfile_tar'], (7) $_CONFIG[sqldump], (8) $_CONFIG['mysql_host'], (9) $_CONFIG['mysql_pass'], (10) $_CONFIG['mysql_user'], (11) $database_name, or (12) $sqlfile variable.