WordPress allows uploads of the following file extensions by default:
Images: .jpeg, .jpg, .png, .gif, .ico
Documents: .pdf, .doc, .docx, .ppt, .pptx, .pps, .ppsx, .odt, .xls, .xlsx, .psd
Audio: .mp3, .m4a, .ogg, .wav
Video: .mp4, .m4v, .mov, .wmv, .avi, .mpg, .ogv, .3gp, .3g2
To upload a file extension other than the above, you will need to add the following code to your wp-config.php file:
define('ALLOW_UNFILTERED_UPLOADS', true);
For security reasons we would recommend that you remove the above line from your wp-config.php file once you have completed the file upload.