Re: Slackware Shadow Insecurity

[daia () stoilow imar ro (Liviu Daia)]

On 13 July 1998, Richard Thomas <rthomas () SY NET> wrote:
> Discovered by Ted Hickman:
>
> Recently I noticed something rather "insecure" about the slackware 3.4
> /bin/login (and probably other versions). If the /etc/group file does
> not exist, any user who logs into the system is given uid 0 gid 0.
[...]

> So whats the fix? Well first of all, change src/login.c to:
>
>         if (setup_uid_gid(&pwent, is_console))
>                 exit(1);

    Not exactly a good idea AFAICT:  I suppose you still want to login
as root to create /etc/group after that...

> If we wanted to be fancy we could continue to login even if
> initgroups() fails (most likely you don't "need" those extra groups to
> get into the system and fix it), but we gotta save something for the
> shadow authors. =)
[...]

    As I said, you'd probably have to do that anyway.

    Regards,

    Liviu

--
Dr. Liviu Daia                   e-mail:   daia () stoilow imar ro
Institute of Mathematics         web page: http://www.imar.ro/~daia
of the Romanian Academy          PGP key:  finger daia () stoilow imar ro