Bugtraq: Re: BUG in /bin/bash

[strombrg () hydra acs uci edu (Dan Stromberg)]

This worked on all the unix variants I tried except debian linux, which
uses bash for sh instead of "the real sh".  I no longer have a copy of
ash to try.

I tried:

Solaris 2.4
Debian linux 1.1
Irix 5.2
OSF/1 3.2
SunOS 4.1.1
Ultrix 4.2

Sure sounds like this interpretation of ^ comes from upstream...

Roger Espel Llima wrote:
> > > VULNERABILITY:  A variable declaration error in "bash" allows the character
> > >                 with value 255 decimal to be used as a command separator.
>   That reminds me of a similar "little-known feature" on SunOS and
> Solaris, where /bin/sh interprets '^' as a synonym for '|' :
>
> $ sh -c 'echo blah ^ cat'
> blah
>
>   Again this could be exploited to fool CGI scripts (and ircII scripts
> too) which execute shell commands with user-supplied data, after
> checking for things like ';', '|' and '&'.
>
>         -Roger
> --
> e-mail: roger.espel.llima () ens fr
> WWW & PGP key: http://www.eleves.ens.fr:8080/home/espel/index.html