Re: [WEB SECURITY] Universal XSS with PDF files: highly dangerous
2. While thinking more about this solution, I observed that if the attacker
can have an "agent" sharing the same IP address with the victim (by agent I
mean an entity that can communicate with the target web site and read back
its response data), then the algorithms I suggested will not be effective.
Note that an attacker can share IP address with the victim when both share a
forward proxy (e.g. some universities and ISPs), or when the attacker and
victim share the same machine (multi-user environment). Still, that narrows
down the attack surface significantly.
It should be noted that this isn't as rare as just a few universities
and ISPs. This also happens in lots of corporate networks (rogue user
on the internal network), it happens with lots of internet cafe's, it
happens with AOL (~5MM users) and it happens with TOR users. So while,
yes, I agree it is better than nothing it is hardly a rock solid
solution for anyone on a shared IP.
-RSnake
http://ha.ckers.org/
http://sla.ckers.org/
http://ha.ckers.org/fierce/