File uploading vulnerabilities question

[Anon]

why should i use is_uploaded_file and move_uploaded_file functions??
where is the security hole in copy($file,"path...filename")??

If there's someone who knows the reason, please post also an example of post-request of this security hole.

Bye
Federico

[nightowl]

who told you to use other functions? as far as I know just copying the uploaded file is good. You might want to check if it is the right format (eg you might only want .gif or .jpg files) and thats when functions come in.

[Anon]

But if you go to the manual page in php site, in the section "Handling file uploads" there's written that you should use them for validating purposes, but i'm not able to think which are they.

If you look at that page, there's a note that say that is extremely dangerous use only a copy command, and in certain cases, it can hang up the computer !!?!?

I'm confused..., i don't know what to think...

Federico

[nightowl]

validating is checking whether the file requested is indeed the file they upload. That might be usefull, it might be useless.

it depends on the case. If you want a form to upload pictures which can be placed online on your website, automatically by a script, you might want to make sure users only upload pictures, not word-documents. in such a case, use validation.

if you only store the files on your server, there is no danger and you don't have to validate.