The first bug for Android has surfaced the bug effects the G1 firmware RC29 and below.The bug interprets few words as system commands and executes them with superuser privileges.

A bug report sent in to Google outlined the issue:

I was in the middle of a text conversation with my girl when she asked why I hadn’t responded. I had just rebooted my phone and the first thing I typed was a response to her text which simply stated “Reboot” - which, to my surprise, rebooted my phone.

To see for yourself if you’re vulnerable, from the home screen select Menu > Settings > About phone, and look for the Build number.If you see this:

kila-user 1.0 TC4-RC29 115247 ota-rel-keys,release-keys,

then you are vulnerable. Anything later than RC29 will be ‘fixed’.

You can also check to see if phone id vulnerable to this bug by typing these 8 keystrokes: <return>-r-e-b-o-o-t-<return>. Your device should reboot if you’re running RC29 or earlier.

Note : save all your work before this out.

A new firmware update (RC30) is being rolled out to G1 owners to fix the issue.

Here’s a workaround for the bug untill a patch is released in the next version:

Open the keyboard and type these 5 keystrokes:

<return>-c-a-t-<return>.

That will cause the phantom shell to not listen to commands any more, at least until the next reboot. –WorkAround Via ZDNET

-Source : intoMobile