[AusNOG] Issues receiving from TPG Mail servers.

[Michael Junek]

Addressing the issue at hand, can you set your MTA not to offer STARTTLS command in the EHLO towards the TPG IP addresses, to force them to use the unencrypted channel?


Surely others who have played with their TLS1.2 settings on their MTA's are having this issue as well with TPG; how would they have gotten around it?


M.




________________________________
From: AusNOG <ausnog-bounces at lists.ausnog.net> on behalf of Bradley Silverman <bsilverman at staff.ventraip.com>
Sent: Monday, 23 July 2018 15:40
To: Mark Newton
Cc: ausnog at lists.ausnog.net
Subject: Re: [AusNOG] Issues receiving from TPG Mail servers.

@Michael - I agree that turning it off is the best way of solving it, the issue is we don't have the servers forcing TLS, that's TPG.

@Mark - These are shared hosting servers, think cPanel & Plesk. The one server is both mail, and website. Which means that the server has websites that accept credit card payments, and therefore is subject to PCI. Any system that is on that server is required to comply with PCI.

If the server was website only, then I'd agree 100% that it would be out of scope for PCI, but since the same server runs both email and websites for shared hosting customers, it is in scope.

We have zero issue with any other MTA, it is only these TPG MTA's that are forcing both TLSv1.0 and an old cipher. If they either turned off TLS or upgraded to TLSv1.2 they would be up to spec.

But we either have to make the decision to block TPG from being able to send to the 100,000s of email accounts we have, or make it so that none of our customers servers are PCI compliant. I'd rather speak to TPG and work with them to fix the underlying problem.

Regards,

Bradley Silverman | VentraIP Australia
Technical Operations

mobile. +61 418 641 103
phone. +61 3 9013 8464

On Mon, Jul 23, 2018 at 3:34 PM, Mark Newton <newton at atdot.dotat.org<mailto:newton at atdot.dotat.org>> wrote:
But PCI Compliance only applies to the Cardholder Data Environment.

Why on earth would you have a mail server in the Cardholder Data Environment?

And if it isn't in the CDE: You can run whatever version of TLS you want, and it's none of PCI's business.

  - mark



On Jul 23, 2018, at 3:06 PM, Bradley Silverman <bsilverman at staff.ventraip.com<mailto:bsilverman at staff.ventraip.com>> wrote:

Hi Matt,

Really appreciate you sending me that email, I will definitely send an email through to there!

@Mark Certainly not! PCI Compliance requires that TLSv1.0 be disabled on the server. Postifx/Exim/Dovecot are not exception to the rule, if we disable TLSv1.0 on the server and remove the weak cipher, then TPG's MTAs aren't able to send mail to us.

Regards,

Bradley Silverman | VentraIP Australia
Technical Operations

mobile. +61 418 641 103
phone. +61 3 9013 8464

On Mon, Jul 23, 2018 at 2:48 PM, Mark Newton <newton at atdot.dotat.org<mailto:newton at atdot.dotat.org>> wrote:
You're trying to exchange payment card information over email?

  - mark

On Jul 23, 2018, at 1:30 PM, Bradley Silverman <bsilverman at staff.ventraip.com<mailto:bsilverman at staff.ventraip.com>> wrote:

Does anyone have a contact at TPG regarding their mail servers?

We are having issues with their mail servers using non-PCI compliant ciphers which is stopping our servers accepting mail from them.


Regards,

Bradley Silverman | VentraIP Australia
Technical Operations

mobile. +61 418 641 103
phone. +61 3 9013 8464
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