RE: priviledge escalation techniques

From: John Cobb (johnc@nobytes.com)
Date: Mon Jan 17 2005 - 17:44:58 EST


You could always do the classic 'at 12:00 /interactive cmd.exe' to gain your
self a command prompt with 'SYSTEM' privileges (well with win2k, havent
tested xp)

E.g.:

C:\>at 22:39 /interactive cmd.exe
Added a new job with job ID = 1

C:\>

In a new window...

C:\>whoami
SYSTEM

C:\>

Bing :)

(also works nice with cygwin ;) )

Regards

John Cobb

www.NoBytes.com
 
Web Design, Web Hosting, Hardware, Software, You Name it, if its to do with
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-----Original Message-----
From: jnf [mailto:lists@innocence-lost.net]
Sent: 17 January 2005 19:45
To: miguel.dilaj@pharma.novartis.com
Cc: pen-test@securityfocus.com
Subject: Re: priviledge escalation techniques

> 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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