Ray Cromwell: YET ANOTHER BAD NETSCAPE HOLE!

Perry E. Metzger (perry@piermont.com)
Fri, 22 Sep 1995 08:46:24 -0400

Ray has been finding lots and lots of buffer overflow bugs in netscape
-- http: url's with overlong domain parts fandango on stack, possibly
permitting you to execute arbitrary code on people's
machines. However, he just found this fun thing!

------- Forwarded Message

From: Ray Cromwell <rjc@clark.net>
Message-Id: <199509220830.EAA13828@clark.net>
Subject: YET ANOTHER BAD NETSCAPE HOLE!
To: cypherpunks@toad.com
Date: Fri, 22 Sep 1995 04:30:03 -0400 (EDT)

>
> On the bright side, mailto: hyperlinks containing extra-long domain names
> seem to be handled comparatively safely in both Netscape and Mosaic.
> (Perhaps they just have longer buffers ? ;)

  Good question. My guess is, Netscape doesn't do any processing on the
mailto: hyperlink at all, but merely passes it to a real mail delivery
agent like Sendmail (or it uses MAPI under Win'95). Which begs
the question, if Netscape is executing an external delivery agent,
there may be the possiblity of sneaking an attack in there and getting
the shell to execute something.

Hmm, let me try something.


WOW!! Unbelievable! Stop the presses! I Can't believe no one ever discovered
this before! Try a page with the following URL

<a href="mailto:blah@foo.com|xterm&"> test </a>

Muahaha! Yet another security hole! Clicking on this mailto brings up
an xterm on my machine!  Simply change the xterm& to "rm -rf /" and
bingo!


Sheesh. I better stop before I am on Netscape's most hated list.


- -Ray



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