Re: [Dovecot] dovecot security with IPv6

2011-06-27 Thread SM

At 01:23 23-06-2011, KÄrlis Repsons wrote:

particular services, please give me your opinion if it's insecure to
have a dovecot server, which is accessed through a public IPv6
address...


If you do not consider it as secure to run a 
Dovecot server on a public IPv4 address, the same applies for IPv6.


Regards,
-sm 



Re: [Dovecot] dovecot security with IPv6

2011-06-23 Thread Noel Butler
That clown is a tad over paranoid...

The only real issue with devices using ipv6 is that most people become
relaxed with security, preferring with ipv4 to do it all on the NAT box,
with ipv6 there is no NAT, so if you have 5 machines, you need to
configure full security on all.
If you're an ISP/OSP/ESP, then you should already have appropriate
security via your router and server, just remember though,
if using  linux you need to use ip6tables  -as well as-  iptables in
your firewall rules script.

There is absolutely NO security risk in exposing any server port to the
net, be it dovecot, apache, or bind ... or, whatever.

On Thu, 2011-06-23 at 08:23 +, Kārlis Repsons wrote:

> Hi Timo, hi all others!
> 
> In fact, I've only read one person claiming that IPv6 support opens up
> "too many backdoors" [1], but anyway, as I intend to run just
> particular services, please give me your opinion if it's insecure to
> have a dovecot server, which is accessed through a public IPv6
> address...
> (or note just shortly what else could give a firm ground to such claims...)
> 
> [1] http://forums.gentoo.org/viewtopic-t-882557.html




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Re: [Dovecot] dovecot security with IPv6

2011-06-23 Thread Willie Gillespie

On 06/23/2011 02:23 AM, Kārlis Repsons wrote:

Hi Timo, hi all others!

In fact, I've only read one person claiming that IPv6 support opens up
"too many backdoors" [1], but anyway, as I intend to run just
particular services, please give me your opinion if it's insecure to
have a dovecot server, which is accessed through a public IPv6
address...
(or note just shortly what else could give a firm ground to such claims...)

[1] http://forums.gentoo.org/viewtopic-t-882557.html


I can't think of any backdoors introduced in IPv6.  The trouble I 
foresee with IPv6 and email won't concern Dovecot, but some spam filtering.


Since the IPv6 address space is large, people can't expect to be 
successful by blocking spammers IP addresses one-by-one.  Instead they 
will end up blocking entire subnets if that's a route they choose to go.


I know that Dovecot slows down/delays login attempts with multiple 
authentication failures.  I guess the question to ask is whether this is 
source IP-based, or user name-based, or both.  Anyone know the answer to 
this?


If it's source IP-based, then if I was an attacker with an IPv6 subnet 
assigned to me, I would just come at it with a different IP address each 
time to avoid the slowdown.


In short, that's the only real potential issue I could see.

Willie


[Dovecot] dovecot security with IPv6

2011-06-23 Thread Kārlis Repsons
Hi Timo, hi all others!

In fact, I've only read one person claiming that IPv6 support opens up
"too many backdoors" [1], but anyway, as I intend to run just
particular services, please give me your opinion if it's insecure to
have a dovecot server, which is accessed through a public IPv6
address...
(or note just shortly what else could give a firm ground to such claims...)

[1] http://forums.gentoo.org/viewtopic-t-882557.html