IE 5.x keep-alive session hijacking
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 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
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 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. Possibly
that can be caused sometimes on other browser configurations as well.