Exchange 2019 and WAF configuration - how to get ActiveSync working ?

Nothing ? Really ?
Again "lost in space" with XG ?

Nothing ? Really ?
Again "lost in space" with XG ?

There are German external Posts about how to integrate this: https://www.frankysweb.de/sophos-xg-18-webserver-protection-und-exchange-2019/

Simply use MAPI and the predefined Policies, should work. 

Contact your Sophos Partner to get assistance for the configuration. 

On the other hand, maybe its time to look at O365 / Exchange Online for certain reasons. See the vulnerabilities coming up in Exchange on Prem,. 

Dear Toni,

thanks for the fast reply but the configuration recommended by you doesn't work.
This has been reported at least two times.

There have been some requests in the community, referring to this issue.
See here: https://community.sophos.com/sophos-xg-firewall/f/discussions/126770/sfos-18-waf-for-owa-exchange-2016-2019
and here: https://community.sophos.com/sophos-xg-firewall/f/discussions/127019/waf-with-exchange-2019-activesync-does-not-work
No solution was found and both discussions were closed.

Which is exactly the reason for my post.
In business environments an Exchange is pretty common.
Thus it would be helpful to
- resolve a known issue
- provide a KB article about best practice as there has been in the past

Especially in times of Hafnium and other security breaches, I prefer to have the strictest configuration possible.
And who else but the maintainer of the product cann tell, how to acheive this.
Thus I kindly ask for some assistance of the Sophos Team on this topic.

Best Regards
ranX

First of all, if you are concerned about Security (which you should) the better approach is to migrate to a hosted service like Microsoft Online. Simply because you cannot keep up with the up2date processes nowadays anymore. Weekly critical security vulnerabilities on Exchange seems to be a good indicator to move to a more stable platform. 

If you want to integrate a WAF with Exchange and it does not work, you should consider to contact a Sophos Partner or Sophos professional service. They can help you with the configuration and can figure out, if it is not supported anymore or if there is an issue. https://www.sophos.com/en-us/support/professional-services.aspx

Most of my customers in Germany migrate to O365 because of the security concerns and because they are not able to keep the exchange up to date anymore. 

To integrate a WAF with Exchange is a standard task,
so your company should still be able to provide guidelines about how to do it.
It was possible with UTM; why not with XG ?

Why should I contact a Sophos Partner ?
The first unanswered post: https://community.sophos.com/sophos-xg-firewall/f/discussions/126770/sfos-18-waf-for-owa-exchange-2016-2019
was opened by a Sophos Gold Partner, certified as XG Architect and Technician.
I bet, he had a similar customer request.
Even that guy wasn't able to resolve the issues and ended up here with no help.

By the way:
I did not ask for pros and cons of O365 versus self hosted on premise Exchange.
I asked for a technical advice and that's what I still hope to get here.

Doesn't Sophos have the expertise any more, to publish a direction like this
https://support.sophos.com/support/s/article/KB-000038003?language=en_US for their recent products ?

Best Regards
ranX

Hi RanX,

In regards to your suggestion about an XG-version of KB-000038003, here's the related KB:

• Sophos Firewall: Web Application Firewall for Exchange 2016

As well, here are related Product Documentation links to also reference:

• https://docs.sophos.com/nsg/sophos-firewall/18.0/Help/en-us/webhelp/onlinehelp/nsg/sfos/concepts/FirewallWAFRules.html
• https://docs.sophos.com/nsg/sophos-firewall/18.0/Help/en-us/webhelp/onlinehelp/nsg/sfos/learningContent/WAFProtectWebServerAgainstAttacks.html 

Please note our Product Documentation Community group where you can provide feedback and suggestions to the team as well. 

Hi Flo,

at first thank you and your team for the reply and the fast publication of the KB article !
The more I'm sorry to say, there is some mistake in the proposed configuration.

I first created the rules as shown and then triple checked them before activation.
When activated, I'm not able to fetch mails on my mobile any more (iPhone with latest iOS) .
I receive the message, no contact to the server could be established.

When I checked the XG log first, I saw, that my phone's IP (german Telekom range) was blocked because of bad reputation.
So I disabled the reputation check in the respective policy.
Afterwards I did a relogin at my mobile network, to receive a different external IP.
Then I tried again but received the same message.

This time the log showed "Inbound anomaly score exceeded" for the reason of WAF Anomaly on the folder /Microsoft-Server-ActiveSync..

Thus I switched back to my working configuration, where only the sending of email attachments fails.

So I kindly ask your engineers, to re-check the published KB article.

About LuCar Toni's comment, to switch to O365 Exchange Online:
This is not an option because, I only replace one evil with another.
GDPR does not allow to use a hosting service, which is subjected to american regulations.
So I simply can't do this without getting in conflict with our law.

Best Regards

ranX

Just wondering, which law and country does restrict/prevent you from using O365? Just curious.

GDPR is mandatory all over Europe:
see https://gdpr.eu/

Here some more information about the impact on O365.
https://www.mondaq.com/germany/privacy-protection/1081800/eu-data-protection-officer-initiates-proceedings-against-institutions-of-the-european-union-for-using-amazon-aws-and-microsoft-office-365

To put it short:
In Europe you are not allowed to transfer your data to a country, which doesn't respect privacy and has the option to access personal data.
The US government forces all US companies, to give access on demand.
Thus the use of hosted services, which process personal data, like email in Exchange online, is not legal for a european company.

That would mean, O365 is actually 0 use cases and customers, but Microsoft reports XXX % Revenue increase per year. 

So how can they use O365, if this is not legally possible? I am just curious. Are all those customers simply ignoring the GDPR? Can i sue all O365 customers based on GDPR? Why is this not going on right now? I am just wondering. 

@ Toni:

Yes, all european customers using Exchange online do ignore GDPR.
Depending on the country, where you live, some authorities are strict, some don't care and I think some european countries don't even know, they're subjected to this ...

In Germany, they are pretty strict and it can become expensive.
It's pretty new and not widely known, that german courts started to make decisions against O365.

A short time ago, I took part in an online security workshop with a bunch of professionals.
One provider told, that a number of customers went to Exchange online after the Hafnium desaster.
And he pointed out, this was no wise decision, because they simply switched from one "unsafe playground" to another.

If you like to, you will be able to successfully sue O365 customers, as soon, as they decide to process personal data on Microsoft O365 services like Exchange online..
And e-mails are definetly persional data --> https://www.gdpreu.org/the-regulation/key-concepts/personal-data/

@Flo:

to keep the focus on the original topic, I remind you, the KB contains some error, as I cannot connect to ActiveSync, when applying the rules as suggested.
The clients get blocked because of bad reputation; when disabling the check, I receive WAF anomaly errors.
Any help on resolving this is highly appreciated.

Best Regards
ranX