Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <51CA9107.6060402@redhat.com>
Date: Wed, 26 Jun 2013 16:58:15 +1000
From: Garth Mollett <gmollett@...hat.com>
To: oss-security@...ts.openwall.com
Subject: Re: KDE Paste Applet

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On 06/26/2013 03:06 PM, Kurt Seifried wrote:
> On 06/25/2013 10:39 PM, Michael Samuel wrote:
>> On 13 June 2013 10:02, Michael Samuel <mik@...net.net> wrote:
> 
>>> Ok, so the fix for this uses KRandom::random()...
>>> 
>>> I suggest leaving the KDE Paste fix as-is and replacing
>>> KRandom with something that just fills an integer from
>>> /dev/urandom - then we can save a few CVE numbers for the rest
>>> of the year.
>>> 
>>> qrand() should probably also do the same, especially since 
>>> cnonces for HTTP auth are using it - that means there's only
>>> 2^32 (at best) possible cnonces...
>>> 
>>>> 
>>>> 
>> Fedora and Ubuntu have both pushed out this patch.  Requesting a 
>> new CVE for "KRandom::random() isn't a secure PRNG", since the
>> KDE guys are convinced that it is.
> 
>> Regards, Michael
> 
> So the thing is it can be completely random, just like a coin
> flip. But the search space might be to small (e.g. a 1 bit key
> based on a coin flip wouldn't be "secure"). I suspect 2^32 isn't
> enough any more either, assuming a 480 core GPU, if you can run 250
> cracking attempts per second per core you can brute force a 2^32
> search space in 10 hours or so. Needless to say GPUs are getting
> pretty cheap. So this appears to be a textbook example of CWE-334
> "Small Space of Random Values".
> 
> Please use CVE-2013-2213 for KDE KRandom::random() CWE-334: Small 
> Space of Random Values.
> 
> 

If /dev/urandom can't be opened it looks even worse:

00041             // No /dev/urandom... try something else.
00042             srand(getpid());
00043             seed = rand()+time(0);

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.13 (GNU/Linux)

iQEcBAEBAgAGBQJRypEHAAoJEPjpLwZKQ8Gp3boIAMy5abrxcwaSuPQYswPtrD2j
Xhj8qYmvwoRQDN5TDaT6uzEMZOSsC7cCv7RarueCiQwX+TOMz/XaxiFE8n37khTk
MgVuBDJc759QNfIIeyYedg7WrT0c3rbqbD/CHjKicJrnpDSTBqxz7um0CejtQzMP
dC1gk2PHYbHzQR75xEYhHPZsY30tsIeY/cP6/x+nN3h7xcVOwKNSLEHEAFzpxH6i
zgCSUj277b0LpmddMIaLvO+qXDEAZ+RT6JN14uqfSYFbQ1F+oM4x4x/k5IOCoHNQ
aAGLSfpxQ+MiborqQKCpGvoMsP9Hdw1s6pnPeDFoLD8tIjxr4Pcem0r5ebiT+zQ=
=Vgdc
-----END PGP SIGNATURE-----

Powered by blists - more mailing lists

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.