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.
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.