oss-sec mailing list archives

Re: CVE for Kali Linux


From: Marcus Meissner <meissner () suse de>
Date: Tue, 24 Mar 2015 11:51:21 +0100

On Mon, Mar 23, 2015 at 10:41:01PM +0100, Marcus Meissner wrote:
On Tue, Mar 24, 2015 at 12:13:06AM +0300, Alexander Cherepanov wrote:
On 2015-03-23 13:38, Marcus Meissner wrote:
There are some attacks even if you verify signatures, e.g. serving
old, known-vulnerable versions. HTTPS can help here (until
signatures start to be widely accompanied by expiring timestamps or
something).

SUSE has added an expiry tag in the YUM metadata for such cases.

It's nice to see progress in this area. Does SUSE guard against
other attacks from [1] too?

[1] https://isis.poly.edu/~jcappos/papers/cappos_pmsec_tr08-02.pdf

Our statements from 2008 (7 years ago) still stand and our package
manager does the full repository signing since 2006 already.

https://lizards.opensuse.org/2008/07/16/package-management-security-on-opensuse/

"Endless Data Attack" is open, as it is hard to solve for openSUSE with
its public mirror system.

The expiry was something added a bit later after the paper to address
the downgrade and replay attacks.

Some more notes.

While the "Update Scenario" is well covered, we are of course facing issues of "bringing up a system".

Like discussed in the thread, how does the customer find a known good ISO image
for download.

While our installer is protecting itself with GPG signatures, but there is need for
the root of trust of the CD medium itself.

So for SUSE we publish SHA256 checksums on the https://download.suse.com/ website at least.
For openSUSE the GPG/SHA and MD5 are on http://software.opensuse.org/132/de .

Ciao, Marcus


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