[whatwg] element "img" with HTTP POST method

[Tab Atkins Jr.]

On Thu, Dec 9, 2010 at 11:01 AM, Adam Barth <w3c at adambarth.com> wrote:
> We've seen use cases for a similar feature for iframes and hyperlinks.
>  For example:
>
> <a href="/logout" post-data>Logout</a>
>
> would be more semantically correct that just <a
> href="/logout">Logout</a> because it would generate a POST instead of
> a GET.

Why wouldn't <form method=post
action=/logout><button>Logout</button></form> work, with some CSS to
make it look like a link if you wanted that?


On Thu, Dec 9, 2010 at 11:41 AM, Philipp Serafin <phil127 at gmail.com> wrote:
> There are quite a number of older web forums that sanitize their HTML using black lists and would not strip new attributes like "post-data". For malicious users, it would be very easy to include e.g. <img src="./do_post.php" post-data="thread_id=42&post_content=Go visit (some spam URL)"> in their signature and have users doing involuntary posts by simply viewing a thread.

Indeed.  You shouldn't be able to trigger POSTs from involuntary
actions.  They should always require some sort of user input, because
there is simply *far* too much naive code out there that is vulnerable
to CSRF.

~TJ