Multiple directory traversal vulnerabilities in TikiWiki 1.9.8.1 and earlier allow remote attackers to include and execute arbitrary files via an absolute pathname in (1) error_handler_file and (2) local_php parameters to (a) tiki-index.php, or (3) encoded "..%2F" sequences in the imp_language parameter to tiki-imexport_languages.php.
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.