Re: Holes in the firewall of Mac OS X Leopard

On Mon, 29 Oct 2007, Brandon S. Allbery KF8NH wrote:

> On Oct 29, 2007, at 17:49 , Juergen Schmidt wrote:
>
> >- if you set it to "Block all incoming connections" it still allows access
> >to certain system services. We could access the ntp daemon that is running
> >per default over the internet. In a LAN based scenario, we were able to
> >query the Netbios naming service even with full blocking enabled.
>
> The firewall in Tiger, and presumably Leopard, only affects TCP services by
> default (you can enable UDP filtering in the Advanced settings). So no change
> here from the status quo.

Nope -- the behaviour we observed did not depend on the protocol by any means. For example we were able to connect to a netcat server listening on a TCP port despite of "Set access to specific services and programs" and an empty list of allowed services.

There is no way to "enable UDP filtering" in Leopard either -- at least I have not found any. In fact the firewall does not use ipfw rules at all.

bye, ju

-- 
Juergen Schmidt, editor-in-chief heise Security www.heise-security.co.uk
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