ZFS and block deduplication

[Bill Bogstad]

On Wed, Apr 27, 2011 at 11:51 AM, Richard Pieri <richard.pieri-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org> wrote:
> On Apr 27, 2011, at 9:50 AM, Edward Ned Harvey wrote:
>>
>> Difficult, but certainly not impossible if verification is disabled.
>
> Unless there is something that I am missing, an attack of this sort is simple in an environment with automated updates.  Take a Debian system using cron-apt to install security updates.  I can identify what is currently installed with 'dpkg -l'.  From this and a mirror copy I can identify what will be installed during the next update.  Determining the update schedule is as simple as looking at /etc/crontab.  By default, anacron on Debian runs the cron.daily scripts at 6:25 AM.  So, with less than 2 minutes work I know what and when.  Now I can pick an executable that I know will be (re)started as root, and there are plenty to choose from.  Let's say apachectl.
>
> The only difficulty is working up an exploit with a matching hash before 6:25 AM tomorrow.

If you are monitoring bug fix channels and can replicate the build environment,
you MIGHT get a larger window.  Don't forget to use Amazon's EC2 to do
the heavy lifting as well.

Bill Bogstad