From: jnf (lists@innocence-lost.net)
Date: Mon Jan 17 2005 - 14:45:05 EST
> and the guys at Micro$oft comit the cardinal mistake of not
> making IT check if SHIFT was pressed 5 times, but to include that in some
> other part of the OS (kernel? ;-)
And while I sit here eating lunch it occured to me how silly of a
statement that was- consider which is more of an acceptible risk-
scenario 1) sethc.exe is run as a normal user, or rather as the user
logged in- it does not run with any special capabilities, the keyboard
driver or whatever intercepts and detects shift pressed 5 times, or held
for X seconds- however
IF someone managed to override your DAC's/file permissions then they can
overwrite the program, however if this occurs- the game is already up
because you had a more critical flaw some place else, and that is really
the way that you lost control.
scenario 2) sethc.exe is always running and monitoring keystrokes looking
for any sequence of keystrokes that it recognizes, in order to do this
either any user has to be able to 'sniff keystrokes', OR, it has to run
with special access allowing the window for abuse to grow bigger- in
addition to this the kernel has to take extra steps in order to pass every
keystroke to userspace, which is going to degrade performance. So here,
the simple program is now running with elevated status and becomes a huge
potential for abuse.
>From a perspective of security, which is a better design? scenario 2 is
basically what you are suggesting. I love IT Security as well, but its not
nearly as humorous as It Security 'Professionals'
cheers,
jnf
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