cat /dev/urandom

[Lane]

On Tuesday 26 July 2005 18:18, Michael Beattie wrote:
> `cat /dev/urandom` will do just that... it's not also going to run
> code from within that output.
>
> On 7/26/05, Lane <lane at joeandlane.com> wrote:
> > On Tuesday 26 July 2005 17:35, Michael Beattie wrote:
> > > On 7/26/05, Matt Juszczak <matt at atopia.net> wrote:
> > > > Hi all,
> > > >
> > > > Quick question.
> > > >
> > > > shell# cat /dev/urandom
> > > >
> > > > can that executed as root cause any harm to the system?  What if a
> > > > random sequence of `rm *` was generated... would it be executed?
> > > >
> > > > I tried that to fix my terminal and forgot it might cause damage as
> > > > root, even if its just being cat'd to the screen.  I thought I saw
> > > > some files fly by which would indicate an execution of `ls`....
> > > >
> > > > Just curious....
> > >
> > > If you had a file with an rm * in it and you cat'd it would it execute?
> > > _______________________________________________
> >
> > That's a good answer, but what if the command was:
> >
> > `cat /dev/urandom`
> >
> > could /dev/urandom generate arbitrary and potentially executable code?
> >
> > I'm curious, too
> >
> > lane
> > _______________________________________________
Hmmm.... interesting.

if I create a file, test, in the current directory like this:

echo -n ls -al >test

Then type `cat test`

I get a directory listing.

Assuming that /dev/urandom generates something like "ls -al" followed by a 
newline, then it stands to reason that `cat /dev/urandom` will actually 
execute the command "ls -al"

Why is it that this does not hold true for `cat /dev/urandom` ?

Still curious

lane