Re: IE 5.x keep-alive session hijacking
Dear Domas Mituzas,
I can't confirm this behaviour for IE 5.5 and 6.0. May be behaviour your
observe is a result of customer having his own proxy server (for example
something like proxymitron, or some kind of ad killer, etc) before your
transparent proxy and customer's proxy server doesn't strip
Proxy-connection header before resending reply to IE, so IE thinks this
header comes from proxy. This should be treated as proxy server
vulnerability. 3proxy doesn't have one :)
--Tuesday, September 2, 2003, 1:17:41 PM, you wrote to
bugtraq@xxxxxxxxxxxxxxxxx:
DM> Hi,
DM> sorry for being innacurate, but I noticed that our transparent-proxy system
is trying (and even to succeeds at some level) to hijack client http
connections. I asked users to supply us with their
DM> browser versions, and all of resulted answers were MS Internet Explorer. I
didn't have too much time to investigate this issue, but here's how I imagine
the problem. The transparent reverse proxy
DM> provides with Proxy-Connection: header, that can be misinterpretated by
MSIE, so the browser software directs all further requests via proxy solution.
It is possible to answer positively to any
DM> request, so browser continues to use proxy server transparently. Though,
we've got ACLs forbidding such usage of our proxy servers, one can use such
MITM attack to get cookies, input data, etc.
DM> Possibly that can be caused sometimes on other browser configurations as
well.
DM> Best regards,
DM> Domas Mituzas
DM> MicroLink Data
--
~/ZARAZA
Впрочем, важнее всего - алгоритм! (Лем)