First off, you can't simply use cfhttpparam type="file" as you'll end up sending file data with headers included in the body of the request. The WebDAV server will write these headers into the file content and you'll end up with a corrupted file. Instead, the WebDAV spec calls for the entire body of the request to be file data.
That leads us to the following code. You'll see this is uploading a simple jpeg to the WebDAV server. The cffile readbinary file attribute is being set to the full local file path. The cfhttpparams include the typical Content-Type header, but also Overwrite and Translate which are commonly supported and sometimes required by WebDAV servers. The body of the request is the raw binary file data. Simple!
<cffile action="readBinary" file="#loc.images[curr_image]#" variable="loc.curr_binary">
<cfhttpparam type="header" name="Content-Type" value="image/jpeg">
<cfhttpparam type="header" name="Overwrite" value="T">
<cfhttpparam type="header" name="Translate" value="F">
<cfhttpparam type="body" value="#loc.curr_binary#">