Re: 2.4.x/Slackware Init script vulnerability

[Radu-Adrian Feurdean <raf () chez com>]

On Wed, 18 Jul 2001, twiz - Perla Enrico wrote:

> I' ve tested it on Slackware 7.0 with kernel 2.4.5 :
> twisterz:~# uname -r
> 2.4.5
> twisterz:~#
>
> I' ve noticed that , while /var/run/utmp *is* world writable :
> twisterz:~# ls -l /var/run/utmp
> -rw-rw-rw-   1 root     root         4608 Jul 17 02:27 /var/run/utmp
> twisterz:~#
> and also /var/run/gpm.pid is -rw-rw-rw-, *but* modules.dep isn' t writable
>
> twisterz:~# ls -l /lib/modules/`uname -r`/modules.dep
> -rw-r--r--   1 root     root         2688 Jul 16 19:36
> /lib/modules/2.4.5/modules.dep
> twisterz:~#
>
> So it can't be edited, and the exploit can' t work 'cause you can't
> add/change lines to modules.dep.
> I'm going to download Slackware 8.0 and test on it, btw on slak 7.0 keep
> good the possibility of, as you said :

The modules.dep file is 0666 only when using the slackware prepackaged
kernel. If you ever recompile and install your own kernel, modules.dep file is
created by make modules_install, that runs with the umask of your shell
session, and is not recreated at boot time unless you add new modules to
/lib/modules/`uname -r`/

Radu-Adrian Feurdean
mailto: raf () chez com
------------------------------------------------------------
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