lkml.org 
[lkml]   [1997]   [Oct]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [linux-security] Malicious Linux modules (fwd)
On Sat, 11 Oct 1997, Chel van Gennip wrote:
> Olaf Titz <olaf@bigred.inka.de> wrote:
[snip]
> >So it is futile for the kernel to check module integrity - you need a
> >_higher_ trust level. "Higher trust level than the kernel" implies
> >media the kernel couldn't physically write to after the attack. I.e.
> >boot from a floppy and re-install everything from trusted media (CD,
> >backup tapes), check file signatures against separately stored media,
> >etc.
>
> I think RPM is usefull here, RPM is able to verify installed files against
> their origial checksum/signature. One of the basics of security is
> "provability". To improve security these checks on signature could be
> done at regular intervals.

Just remember, it suffers the same weakness as everything else - rpm
can be hacked up as easily as anything else. Olaf is right, once
you've been compromised, booting and comparison against read-only
media is really your only "provable" way of finding out what got hit.

> A medium without modification possibilities (like ROM or CD-Rom)
> or a trusted server should be used to store the signatures or a master
> signature over the files containing the signatures.

...and the rpm binary...and the kernel...and an initrd...and... ;-)

Adam
--
Things look so bad everywhere Adam D. Bradley artdodge@cs.bu.edu
In this whole world what is fair Boston University Computer Science
We walk blind and we try to see Ph.D. student and Linux hacker
Falling behind in what could be ----> Bring me a Higher Love ----> <><


\
 
 \ /
  Last update: 2005-03-22 13:40    [W:0.036 / U:0.076 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site