cd1zz/metasploit-framework — comment on commit 30035ef34cc3e3f1983c81a080348d404a7b5b90
File: modules/exploits/windows/http/sysax_create_folder.rb line 113
By wchen-r7:

If you use the send_request_cgi() function, it'll set the set the content length automatically with set_content_len_header().