Denial of service in KitchenAid blenders

[Jedi/Sector One <j () pureftpd org>]

Product : KitchenAid blenders
Date    : 10/10/2004
Author  : Frank Denis <j () pureftpd org>


   ------------------------[ Product description ]------------------------

  From the web site :

  KitchenAid offers the most powerful premium blenders available. Oversized
stainless steel blades allow it to crush ice at any speed.

  The most powerful premium blender available - features a strong motor and
unique blade design.

  One-piece blade assembly features oversized stainless steel blades on four
different planes for optimal blending.

  Durable base provides maximum stability during mixing.

  The electronic sensor automatically adjusts power to maintain a consistent
speed.

  40-oz. heavy-duty glass jar resists scratching and discoloration, and all
jars and lids are dishwasher safe.

  Home page : http://www.kitchenaid.com/


      ------------------------[ Vulnerability ]------------------------

  There's a race condition in KitchenAid blenders that can trigger a denial
of service.

  The device will require a physical shutdown in order to work again.


      ------------------------[ Implications ]------------------------

  The implications are numerous. Chefs can be extremely frustrated, thus
causing severe material and social damage.


         ------------------------[ Exploit ]------------------------
         
  Here's a reliable way to reproduce the race:
  
- Hit the power button ("I"),
- Hit the  "pulse" button.
- Hit a speed button,
- While keeping the speed button, push on the "pulse" button again.

  The device immediately goes in a strange state. LEDs are blinking and
buttons are no more functionnal until the power is off.


    ------------------------[ Affected versions ]------------------------
         
  In lab, the exploit successfully worked on a 5-speed KSB5ER mixer. Its
color was empire red and cold soup was previously inserted in the glass jar.

  Other colors are likely to be affected as well. The silver "pro" model may
be affected as well.


       ------------------------[ Workarounds ]------------------------
         
  No workaround is known yet.
  Never give access to the device to untrusted users.


      ------------------------[ Vendor status ]------------------------
         
  Unfortunately, I wasn't able to find any contact at KitchenAid's for
security flaws in mixer firmwares.

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