Re: BUG #5687: RADIUS Authentication issues

On Sun, Oct 3, 2010 at 18:30, Alan T DeKok <aland(at)freeradius(dot)org> wrote:
> Tom Lane wrote:
>> Hm ... seems to me that is a network security problem, not our problem.
>> Who's to say one of the spoofed packets won't pass verification?
>
>  The packets are signed with a shared key.  Passing verification means
> either the attacker knows the key, or the attacker has broken MD5 in
> ways that are currently unknown.
>
>> If you want to change it, I won't stand in the way, but I have real
>> doubts about both the credibility of this threat and the usefulness
>> of the proposed fix.
>
>  The credibility of the threat is high.  Anyone can trivially send a
> packet which will cause authentication to fail.  This is a DoS attack.

I don't agree about how high it is - unless I misunderstand the
wording. You still need to have unfiltered access to the network that
the database server is on (unlikely) and you need to guess/bruteforce
the port (using bruteforce not really hard, but likely to be detected
by an IDS pretty quickly)

It is definitely an opportunity for a DoS attack though, so it should be fixed.

I find your suggested patches kind of hard to read posted inline that
way - any chance you can repost as attachment or publish it as a git
repository I can fetch from?
--
 Magnus Hagander
 Me: http://www.hagander.net/
 Work: http://www.redpill-linpro.com/