Re: Account Lockouts

[email protected] Thu, 02 Dec 2004 12:52:34 -0500
Newsgroups gmane.comp.security.programming,gmane.comp.security.web-applications
Message-ID <[email protected]>
On Thu, 02 Dec 2004 15:10:21 +1100, Michael Silk said:
> Hi,
> 
>  A pretty easy solution exists and is to use "http://www.captcha.net/"
> images before locking the account.

The obvious problem is that a visually-challenged user is screwed.

The not-so-obvious problem is that although it "proves" the person is a person,
it doesn't prove that the person who entered the response is the "alledged
person or script" you sent the image to.

Some spammers have found a way to deal with these - they grab the image, and
pass it through to some *other* user as a captcha to get into a "free porn"
site or similar.  So the user sees it, types it in for the spammer, and then
the spammer redirects the response to whoever originally sent it.
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