[wp-hackers] Trackback Spam Fix

[Mark Jaquith]

Elliott Bäck wrote:

> As far as I know, the trackback form doesn't verify that the trackback 
> URL resolves to the host IP sending the trackback, which in my opinion 
> and experience, is the cause of most or all of the trackback spam 
> currently getting posted.  I know that in theory trackback can be send 
> by a server of behalf of someone else, but I know of very few 
> implementations that work that way.
>
Another good thing to do is to check the sending URI to see if there is 
a link to the TBed page.  I know it isn't technically required, but a 
lot of people consider it to be a form of "quasi-spamming" when other 
bloggers Trackback without linking.  Spam Karma 2 currently does that 
check, but the IP check might be just as effective.