[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]

Re: Insecure Privoxy Configuration in Vidalia Bundles Prior to 0.1.2.18





On 10/31/07, Gregory Fleischer (Lists) <gfleischer.lists@xxxxxxxxx> wrote:
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Versions of the Vidalia bundle prior to 0.1.2.18 install Privoxy with
an insecure configuration file.  Both Windows and Mac OS X versions
are affected.  The installed 'config.txt' file ('config' on Mac OS X)
had the following option values set to 1:

   - enable-remote-toggle
   - enable-edit-actions

Additionally, on Windows the following option was set to 1:

   - enable-remote-http-toggle

Malicious sites (or malicious exit nodes) could include active content
(e.g., _javascript_, Java, Flash) that caused the web browser to:

   - make requests through the proxy that causes Privoxy filtering to
     be bypassed or completely disabled

   - establish a direct connection from the web browser to the local
     proxy and modify the user defined configuration values

The Privoxy documentation recommends against enabling these options in
multi-user environments or when dealing with untrustworthy clients.
However, the documentation does not mention that client-side
web browser scripts or vulnerabilities could be exploited as well.

It should be noted that using Tor is not a prerequisite for some of
these attacks to be successful.  Users of Tor may be at greater risk,
because malicious exit nodes can inject content into otherwise trusted
sites.

In order to allow time for people to upgrade, additional attack
details and sample code will be withheld for a couple of days.

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.7 (Darwin)

iD8DBQFHKKB6WbVJrJm/lrsRApQLAKC5FRcVsCuBBxtSxnmbl0ihixaX3gCfZHZ8
gwXIIv2LUswWy1bSwg5CJU4=
=ZSdL
-----END PGP SIGNATURE-----


I know what that code would be (cause I tried this awhile back), but I'm not going to be the one to post it.  Although anyone with basic HTML coding abilities and half a brain can figure it out.  And _javascript_/java/flash isn't required to make this happen.  It can be done with a simple IFRAME.  But I'm not posting the one line of HTML code that would do this, no sir.

We noted this a while back with JanusVM, but I don't think we documented the reasoning behind it.
(Cue Roger giving a friendly reminder to get more documentation and source code produced ;-)

First we disabled those options for obvious reasons.  
Then we enabled them because a couple of users wanted more control. 
Then we disabled them again because that level of control can be accessed from the console if they really want it.

Fun times.