Re: [patch 7/8] fdmap v2 - implement sys_socket2

From: Al Viro
Date: Sat Jun 09 2007 - 11:15:43 EST

On Fri, Jun 08, 2007 at 07:10:03PM -0700, Ulrich Drepper wrote:
> Hash: SHA1
> Al Viro wrote:
> > Any real-world examples of exploitable holes based on that?
> Return to libc exploit, calling dup2, where some privileged data is
> redirected from the normal file descriptor to one of the attackers
> choosing. The latter could be an outgoing socket connection which would
> result in leaking the data to the outside.
> normal code intruder
> so = socket()
> fd = open ("local-file")
> dup2(so, fd);
> write (fd, privileged data)
> It's just a little function call. If the arguments of dup2() are known
> this is not a big issue to construct.

So which code is supposed to do that open/write in your example? Library?
Unmodified application? Application specifically modified to make *that*
open() randomized?
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