Bugtraq: Re: Backdoor Paper

[dube0866 () EUROBRETAGNE FR (Nicolas Dubee)]

hello,

you may want to add this "feature" that can act as a backdoor:

when specifying a wrong uid/gid in the /etc/password file,
most login(1) implementations will fail to detect the wrong
uid/gid and atoi(3) will set uid/gid to 0, giving superuser
privileges.

example:
rmartin:x:x50:50:R. Martin:/home/rmartin:/bin/tcsh
on Linux boxes, this will give uid 0 to user rmartin.



-plaguez
dube0866 () eurobretagne fr

> Date:         Sat, 16 Aug 1997 19:07:58 -0400
> From: Christopher Klaus <cklaus () ISS NET>
> Subject:      Backdoor Paper
>
> Here's a paper I wrote on backdoors.  Feedback welcome.
>
>
> Backdoors
>
> By Christopher Klaus 8/4/97