The Image Manager in MOStlyCE before 2.4, as used in Mambo 4.6.3 and earlier, allows remote attackers to rename arbitrary files and cause a denial of service via modified file[NewFile][name], file[NewFile][tmp_name], and file[NewFile][size] parameters in a FileUpload command, which are used to modify equivalent variables in $_FILES that are accessed when the is_uploaded_file check fails.