“Mal-Configured Secure E-Mail . . .”
A new risk arises as Secure Messaging Enters the Late-Majority Adoption Phase!
Another one of those Dan’s New Leaf Posts, meant to inspire thought about IT Governance . . . .
So we’re auditing a bank and they send us files using their shiny new “Secure E-Mail System” and guess what? It’s not secure AT ALL.
Then we notice it happening at another couple of banks, and then at another couple of vendors, so now we’re worried: people are rolling out new systems that give them a false sense of security.
So because we’re seeing this rather often now, we need to get the word out: If recipients are not authenticating to receive documents sent through these systems, you are probably fooling yourself (and your recipients).
As companies adopt secure messaging, they are either selecting the option–or it defaults to the option–that the recipient need not authenticate to retrieve the document. Configuring the secure messaging system in this manner exacerbates the risk of a man-in-the-middle attack.
We’re seeing this primarily with Citrix Sharefile, but we’ve also seen it with other systems. Based on our own experience rolling out several secure message packages, we fear this may be a reaction to recipients complaining that they can not remember their password. While we understand forgotten passwords are an inconvenience, bypassing authentication is NOT an adequate solution.
With our vendors, we can’t really do much about it other than (hopefully) convince them to change their configuration and politely request they do not use it for our information until it is configured properly. In the case of our Clients we hope that it’s caused by these systems being poorly configured by default, because if they’re intentionally bypassing authentication it means they’re not doing proper risk assessments prior to implementing a change!
The above diagram illustrates what a man-in-the-middle attack looks like in this scenario. First though, here’s what should happen: When a new secure message is sent, the system will send an e-mail notifying the recipient of the message. The recipient then clicks on a link in that e-mail that takes them to a secure web page where they SHOULD have to authenticate to get access to the sensitive information.
What we’re worried about–the man-in-the-middle attack–happens when someone inserts an e-mail server into the path that does nothing but copy e-mail messages.
When you do not configure the system to require authentication, the man-in-the-middle has the same access to the sensitive information as the recipient, via the link that is sent in the notice. Keep in mind this could be a person twenty years down the road who discovers the e-mail on a retired server. That’s the problem with unencrypted e-mails: they can be available for years and years.
If the secure message system is configured to require authentication, however, merely having the link offers the man-in-the-middle nothing more than a login page. At this point there’s a good chance any would-be attacker will simply move on to a more attractive target–like an organization which HASN’T configured their secure message system correctly.
But a teachable moment arises here in this age of encrypting everything: data needs to be encrypted both in motion and at rest. If you are not requiring authentication then you are only providing encryption when the data is in transit, when the link is clicked to download the sensitive information. While it’s good that the data is encrypted in motion ANYBODY IN THE PATH can download the information, which is kind of like not encrypting the data at rest!
This approach creates a false sense of security. Malicious servers in the delivery path will surely be adding those secure messaging companies who offer their product configured this way by default to their key-word search.
So please spread the word! And, when you are sent a link to sensitive information that does not require you to authenticate, consider sending this article to the person who THINKS they are protecting information.
Original article by Dan Hadaway CRISC CISA CISM. Founder and Managing Partner, infotex
Dans New Leaf is a fun blog to inspire thought in the area of IT Governance.