[fw-wiz] Firewall Best Practice regarding XMPP traffic?



Hi all,

In securing XMPP (Jabber, IM) servers, what best practice in your
opinion should be used.

Having consulted with the XMPP community, they tend to think of TLS
communication channels only and thus a firewall becomes somewhat
redundant from an XMPP perspective.

That is, the XMPP server should handle authentication, deep packet
inspection, IP address filtering and so forth. (Of course this is a
simplistic view given a
firewall helps prevent unprotected services hosted by the XMPP server
from being exploited and it helps control DoS etc)

However, are XMPP servers deployed in practice like this, where all
that is required of the firewall is opening port 5222 for
client-to-server communication and port 5269 for server-to-server
communication where all traffic is over TLS.

I'd imagine that some enterprises want to inspect at the firewall (or
even by IDS) layer-7 packet payloads. For example, ensure a user with
a JID of xyz@xxxxxxxxxx cannot send packets through the firewall or a
particular malware signature or malicious Web URL that is embedded
with IM conversations is blocked. In such scenarios, is it best
practice to remove the TLS option and thereby loosing some proof of
identify (certificates) in favour of deep packet inspection?

Are there scenarios where an enterprise that is geographically spread
who use VPN's such that they do not require TLS encryption on the XMPP
servers? Rather, they are content that their VPN tunnel is providing
adequate security coupled with DPI (Deep Packet Inspection) of the
XMPP packets and layer 3 and 4 filter also at the firewall?

While XMPP servers such as Openfire have TLS functionality end-to-end,
are these used in practice by security administrators or is some of
the communication desired in the clear for DPI. Presumably, by not
fully considering a firewall chokepoint means that each XMPP service
needs to be updated individually for new threats and there is also a
certificate management issue.

Presumably two XMPP servers that belong to two different enterprises
would not share a VPN channel but use TLS enabled on the XMPP servers
instead. Again, a firewall is not the silver bullet for every scenario
;-)

Would there be scenarios where xmpp clients are not allowed to connect
to the XMPP server except through a HTTP proxy (Perhaps the XMPP
server ports are not externally accessible).

For example, Linux iptables could be used to inspect the XMPP traffic
not just at layers 3 and 4 but some rudimentary l-7 filtering.

Any feedback on personal experiences/scenarios, is greatly welcomed.
regards,
Paddy.
_______________________________________________
firewall-wizards mailing list
firewall-wizards@xxxxxxxxxxxxxxxxxxxxx
https://listserv.icsalabs.com/mailman/listinfo/firewall-wizards



Relevant Pages

  • Re: [fw-wiz] Firewall Best Practice regarding XMPP traffic?
    ... I have taken on board the XMPP administrators views that TLS should ... from reading the various XMPP ... DPI and defense in-depth situations using a firewall. ... simple as opening XMPP service ports and leaving the XMPP server ...
    (Firewall-Wizards)
  • Re: Alternative zu "WhatsApp"
    ... BTDT ... Das kommt auf die Kaputtheit des Servers an. ... Wer XMPP mit google ...
    (de.org.ccc)
  • Re: Enabling tls negotiation in a socket
    ... nice ones for php yet as far as I know - was always one of those projects I ... by pubsub through XMPP for realtime notification so! ... TLS support... ... But in XMPP, the new way of doing stuff with TLS is to open a normal socket, ...
    (php.general)
  • Re: Enabling tls negotiation in a socket
    ... I have a question about opening a normal socket, then negotiating a TLS ... great xmpp lib for AS3 from ignite realitime that makes openfire) but no nice ones for php yet as far as I know - was always one of those projects I really wanted to do but couldn't justify without getting a client to part fund:p ...
    (php.general)