Paket-Management-Systeme unter Linux nur bedingt vertrauenswürdig

Thorsten

SSF Facilitymanagement
Staff member
Linux-Anwender verweisen oft auf die Vorzüge des automatischen Paket-Managements ihrer Distribution, insbesondere wenn es um das schnelle Schließen von Lücken im Kernel und in Anwendungen geht. Die University of Arizona weist in einem Bericht allerdings darauf hin, dass die Paket-Manager Sicherheitslücken aufweisen, mit denen manipulierte Distributions-Mirror-Server dem Client alte Pakete mit Sicherheitslücken unterschieben können. Und dass es relativ einfach ist, einen eigenen Mirror-Server für eine Distribution zu etablieren, haben die Forscher gleich mit demonstriert.

Kompletter Artikel unter heise online - Bericht: Paket-Management-Systeme unter Linux nur bedingt vertrauenswürdig
Quelle heise online
 
Anwort auf die News von der SuSE-Security Liste

Dear openSUSE and SUSE Linux Enterprise users,

Several news sites recently published articles citing a report about
attacks on package managers [1]. Some unfortunately chose a wording
that could be misunderstood as if a rogue mirror server could trick
YaST into installing malicious software when applying regular
(security-)updates.

This is not the case. All official update repositories for SUSE
Linux based products use cryptographically signed packages and meta
data. YaST verifies the cryptographic signatures and rejects any
file whose signature doesn't match. Therefore it's not possible for
a rogue mirror to introduce malicious software.

Another problem outlined in the report was that mirror servers could
intentionally serve an old version of the update repository.
Therefore clients using that mirror would not get the latest
security updates and potentially stay vulnerable to known and
presumably already fixed problems.

SUSE already addresses this issue too.
- Firstly, YaST will not automatically downgrade installed packages.
Therefore an outdated repository can not undo an already applied
security fix.
- Secondly, starting with version 10.3 openSUSE uses a central
download redirector that directly serves the meta data. Stale
mirrors are therefore detected immediately. To avoid sending
clients to mirrors that do not have certain files (yet), the
download redirector also continuously monitors it's mirrors. It
only redirects to servers that are known to have the file in
question.

For SUSE Linux enterprise products only servers owned by Novell
are used via secure https connections.

cu
Ludwig

[1] Attacks on Package Managers

--
(o_ Ludwig Nussel
//\
V_/_ SUSE Linux Enterprise
SUSE LINUX Products GmbH, GF: Markus Rex, HRB 16746 (AG Nuernberg)
 
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