Evaluating 2FA in the Era of Security Panic Theater

(note: this is a writeup of a talk that I gave at DerbyCon 2019 and at UNCC’s CyberSecurity Symposium in 2020. Thought it would be useful to get it in blog form, especially with the Solar Winds event unfolding.)

It seems like today’s world offers constant reminders of how insecure our digital lives can be. As a security professional, part of my job is to monitor for threats to my company and the organizations with which I have a relationship. A significant part of that effort lies in assessing how likely or realistic those threats are. If you believed every infosec vulnerability headline you see come across twitter, it would be easy to feel somewhat like chicken little, with the sky ever falling. I’ve actually coined a term for this phenomenon (though I’m not sure if I actually originated it, but Google seems to think so): Security Panic Theater.

If this term sounds mildly familiar, it is because of its proximity to the phrase ‘security theater’. We experience this pretty regularly whenever we attend a major sporting event like the World Series and we have to go through long lines where people wave a wand over us to ensure my keychain knife doesn’t get admitted to the stadium. This takes place even though the track record of seizing weapons that would matter is pretty poor. But the mere act of this experience makes patrons feel safer. This is even worse when we travel and pass through TSA’s gauntlet of screeners. Consistent penetration tests reveal a woeful rate of actually detecting items that could cause us harm while we are in flight. To add to the insult of this process, there is a comic reality with what actually is seized. I’ll let comedian Steve Hofstetter explain:

If you bring too much liquid, the TSA confiscates it and throws it away, in case it’s a bomb. So they throw it away. In case it’s a bomb. In the garbage can, right next to them. With all the other possible bombs. In the area with the most amount of people.

In case it’s a bomb.

Steve Hofstetter

Security Panic Theater (SPT) is a bit of a different experience. The process for SPT goes something like this:

Vulnerability/breach announced regarding a product or control (x) [Security]

+ Inflammatory internet headline(s) regarding (x) [Panic], which leads to the conclusion:

Product or Control (x) is useless/defeated [Theater]

A relatively recent example of this was the release of a penetration testing toolkit by Polish researcher Piotr Duszyński named Modlishka, which loosely translates in English to Mantis. The central feature of this toolkit was the use of a reverse proxy that could accelerate a phishing flow by sending a user to a spoofed URL, but the rest of the web experience was as the user expected. This enabled a man-in-the-middle (MITM) attack to capture both the credential and the SMS code being used by the user.

The significance of this new framework didn’t lie with the fact that you could now phish any two-factor authentication (2FA) method that used one time passwords (OTP). What made this release notable was that it was now significantly easier to accelerate the phishing flow because you didn’t have to spin up a fake site. A reverse proxy would do the work for you. To be clear, that is certainly noteworthy, but also not new.

However, to hear the twitterverse and online media outlets talk about it, you’d think all our credentials, even if protected by 2FA, were suddenly moments away from being captured by hackers. Now, to be fair, there are some responsible journalists who try to treat these topics fairly, but even a sane article can often be overridden by a clickbait title like “Is 2FA Dead?”

Let’s get a few basics clear for the sake of sanity & clarity:

2FA can’t be killed

2FA represents a combination of factors for authentication, not a single technology or pattern. The last few years alone have had a litany of episodes where a particular technology may be at risk (often temporarily, or misleadingly so), such as:

RSA tokens were allegedly cracked (mostly not true)

SS7 flaw will drain all your bank accounts (true, but hard to implement)

NIST Killed SMS 2FA (sort of, but not really)

Modlishka makes SMS useless (sort of, but not really) 

Google Security keys have Bluetooth flaw (recall for some, not all)

Yubikey FIPS keys flawed (recall for some, not all) 

Apple promoted modifications to SMS 2FA for improved anti-phishing strength & joined FIDO’s board. 

2FA implementation in 2020 Iowa Caucus renders app nearly unusable

And even today as I update this, the SolarWinds hackers bypassed OWA’s 2FA because they compromised the server hosting the private key.

That last one hasn’t had enough oxygen yet for the 2FA headlines to blaze, and they will, but both the company analyzing the hack and Bruce Schneier emphasize:

It should be noted this is not a vulnerability with the MFA provider and underscores the need to ensure that all secrets associated with key integrations, such as those with an MFA provider, should be changed following a breach.

Notice the trend here? While there is some truth for most of these from a vulnerability perspective, the reality is that these technologies still work to protect your credentials. Apple’s recent announcement has its own debate worth talking about (and has been on IDPro’s Slack site) and the debacle in Iowa shows that any technology is a dumpster fire waiting to happen if its implementation is designed poorly.

The diversity of the 2FA landscape makes it stronger, not more vulnerable. 

Let’s take a look at the following categories of authentication: 

Pretty diverse to be killed with a single vulnerability, I would think! Now let’s overlay which ones have at least one known vulnerability:

If we look at all the ones in red, that would be pretty disheartening to the casual observer. That’s where journalists and analysts need to take special care in talking about vulnerabilities. The real story doesn’t fit neatly into a simple headline regarding the vitality of the authentication landscape.

All methods of 2FA are still incredibly effective (some more than others) 

Google published a study of some internal findings on various methods used to secure their public credentials. Yes, SMS should be the low hanging fruit of 2FA but guess what, even this well-beaten pinata of 2FA stopped 76% of targeted attacks and nearly 100% of automated & bulk phishing attacks!

Microsoft recently published some numbers to similar effect, that the risk of account compromise is reduced by 99% using multi-factor authentication (MFA). I’d say 2FA is far from dead in that context.

Yes, we should get rid of the 2 in 2FA, long live MFA*

The biggest reason for this is that users can be more secure, and less inconvenienced when they have access to multiple ways of authenticating instead of one token combined with a password that can be lost, or a phone that can be upgraded and lock a user out. Without promoting one vendor, I can say thoughtfully that I have several methods to secure my key accounts and that diversity of options, I believe, is the key to giving our users the power of choice as to how they want to login. That power is how we eventually do reduce passwords to an edge use case. The key is that more sites need to support those methods to incentivize adoption. We’re not there yet, but the last few years show a lot of promise in eventually achieving that goal.

The reality is, even the coolest methods of authentication will eventually find a vulnerability. History proves this. But we don’t throw the baby out with the bathwater when those are discovered. We fix it, learn from it, and stay secure. Let’s leave the theater to the actors, where it belongs.

* For another blog post, but I’m wondering if MFA needs to be retired as a concept and we simply focus on the strength of authentication. To be continued…