Last Updated: 2013-02-11 17:10:07 UTC
by John Bambenek (Version: 1)
One of the emails that came through on our handlers list pointed out some interesting behavior. When querying a domain (a sample in this case is shineecs.com), the registrar at the end of the response would include an HTML script tag. See output below:
When manually fetching that script, all that was retrieved is: document.write(""), so nothing is modified at this instant in time. The domain in question resolves to an IP that has been implicated in a small number of instances of malware connected to some worm activity, but nothing deeply out of the ordinary. The same is true for the IP connected to the registrar. So why is this happening? The registrar is doing this as a lazy way to do some analytics they find useful, so not malicious in this case.
What is fun, however, is that when I run a WHOIS via the various web tools, most all of them process this HTML tag as HTML instead of text, which means this would be a successful XSS vector if you could maliciously modify a WHOIS record.
In this case, the registrar adds that script tag, not the registrant. That said, if a registrar doesn't properly validate the information put in those fields, evil may ensue (the registrar I use does). Or worse, if the registrar themselves are a bad player, they can do whatever they want. In this case, an innocous issue, but another episode in the ongoing saga of web applications. If you get input from a third-party source, make sure to scrub it to ensure that "bad things don't happen" like XSS.
bambenek \at\ gmail /dot/ com