On 12/19/2016 06:26 PM, Patrick Schleizer wrote:
What about Debian graphical installer security? Isn't that in meanwhile the ideal target for exploitation for targeted attacks? Because it will take a while until the Debian point release with fixed apt. And during the gui installer, the output of apt-get is not visible. And stuff during installer taking a long time is something users have been trained to expect. So I don't think it would raise much suspicion. If exploitation works, fine, if not, nothing was lost. Also Debian gui installer may be distinguishable over the network from already installed systems? Because first it's using debootstrap (perhaps with special options), then apt-get. The timing or something else could make it distinguishable over the network. Best regards, Patrick
Probably so. But an attacker can be opportunistic--try and maybe fail/succeed--whether or not the user is installing or merely updating.
The only solid solution to this issue is to alert users out-of-band, and have them also obtain *new media out-of-band* so they can re-install. In our case on Qubes, dom0 updates can fill the need for obtaining new media. But going forward, the best practice would include issuing new ISOs as well, since users installing Debian alongside Qubes will perform normal updates as a matter of course--they may review new CVEs or QSBs but not from several months prior.
BTW, I think Debian's idea expecting users to validate detailed metadata with their eyeballs is crazy.
Chris