Subject: Re: asking for the path to init.
To: None <firstname.lastname@example.org>
From: der Mouse <mouse@Rodents.Montreal.QC.CA>
Date: 09/20/1999 02:35:46
>> [N]ot the / filesystem, but rather any local filesystem ([...]). If
>> the attacker can boot with the option to prompt for init, the
>> attacker can also specify arbitrary root device and kernel names.
> Not sure. Without devices nodes the game is harder.
The attacker-provided kernel doesn't have to be a "normal" kernel. It
could be little more than fsdb plus enough drivers to talk to the
console and disks. It could be a perfectly ordinary kernel that runs
off your usual root device - EXCEPT that, say, any process that tries
to open the path "/magic/nonexistent/file"...or close(-31337)...or
whatever...magically gets all its uid values set to zero.
Or whatever. The possibilities are limited only by the attacker's
imagination and kernel-hacking abilities. And many of them don't need
device nodes in the usual sense, and many of them use your existing
device nodes but still let the attacker in.
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