The Bane of Backwards Compatibility

I’m a huge fan of video games. I love playing them, especially on my old consoles from my formative years. The original Nintendo consoles were my childhood friends as much as anything else. By the time I graduated from high school, everyone had started moving toward the Sony Playstation. I didn’t end up buying into that ecosystem as I started college. Instead, I just waited for my brother to pick up a new console and give me his old one.

This meant I was always behind the curve on getting to play the latest games. I was fine with that, since the games I wanted to play were on the old console. The new one didn’t have anything that interested me. And by the time the games that I wanted to play did come out it wouldn’t be long until my brother got a new one anyway. But one thing I kept hearing was that the Playstation was backwards compatible with the old generation of games. I could buy a current console and play most of the older games on it. I wondered how they managed to pull that off since Nintendo never did.

When I was older, I did some research into how they managed to build backwards compatibility into the old consoles. I always assumed it was some kind of translation engine or enhanced capabilities. Instead, I found out it was something much less complicated. For the PS2, the same controller chip from the PS1 was used, which ensured backwards compatibility. For the PS3, they essentially built the guts of a PS2 into the main board. It was about as elegant as you could get. However, later in the life of those consoles, system redesigns made them less compatible. Turns out that it isn’t easy to create backwards compatibility when you redesign things to remove the extra hardware you added.

Bringing It Back To The Old School

Cool story, but what does it have to do with enterprise technology? Well, the odds are good that you’re about to fight a backwards compatibility nightmare on two fronts. The first is with WPA3, the newest security protocol from the Wi-Fi Alliance. WPA3 fixes a lot of holes that were present in the ancient WPA2 and includes options to protect public traffic and secure systems from race conditions and key exchange exploits. You’d think it was designed to be more secure and would take a long time to break right? Well, you’d be wrong. That’s because WPA3 was exploited last year thanks to a vulnerability in the WPA3-Transition mode designed to enhance backwards compatibility.

WPA3-Transition Mode is designed to keep people from needing to upgrade their wireless cards and client software in one fell swoop. It can configure a WPA3 SSID with the ability for WPA2 clients to connect to it without all the new enhanced requirements. Practically, it means you don’t have to run two separate SSIDs for all your devices as you move from older to newer. But practical doesn’t cover the fact that security vulnerabilities exist in the transition mechanism. Enterprising attackers can exploit the weaknesses in the transition setup to crack your security.

It’s not unlike the old vulnerabilities in WPA when it used TKIP. TKIP was found to have a vulnerability that allowed for exploiting. People were advised to upgrade to WPA-AES as soon as possible to prevent this. But if you enabled older non-AES capable clients to connect to your SSIDs for compatibility reasons you invalidated all that extra security. Because AES had to operate in TKIP mode to connect the TKIP clients. And because the newer clients were happy to use TKIP over AES you were stuck using a vulnerable mode. The only real solution was to have a WPA-AES SSID to connect to for your newer secure clients and leave a WPA-TKIP SSID active for the clients that had to use it until they could be upgraded.

4Gs for the Price of 5

The second major area where we’re going see issues with backwards compatibility is with 5G networking. We’re hearing about the move to using 5G everywhere. We’ve no doubt heard by now that 5G is going to replace enterprise wireless or change the way we connect to things. Honestly, I’m not surprised someone has tried to make the claim that 5G can make waffles and coffee yet. But 5G is rife with the same backwards compatibility issues present in enterprise wireless too.

5G is an evolution of the 4G standards. Phones issued today are going to have 4G and 5G radios and the base stations are going to mix the radio types to ensure those phones can connect. Just like any new technology, they’re going to maximize the connectivity of the existing infrastructure and hope that it’s enough to keep things running as they build out the new setup. But by running devices with two radios or having a better connection from the older devices, you’re going to set yourself up to have your new protocol inherently insecure thanks to vulnerabilities in the old versions. It’s already projected that governments are going to take advantage of this for a variety of purposes.

We find ourselves in the same boat as we do with WPA3. Because we have to ensure maximum compatibility, we make sacrifices. We keep two different versions running at the same time, which increases complexity. We even mark a lot of necessary security upgrades as optional in order to keep people from refusing to implement them or fall behind because they don’t understand them1.

The biggest failing for me is that we’re pushing for backwards compatibility and performance over security. We’re not willing to make the hard choices to reduce functionality in order to save our privacy and security. We want things to be backwards compatible so we can buy one device today and have it work on everything. We’ll just make the next one more secure. Or the one after that. Until we realize that we’re still running old 802.11 data rates in our newest protocols because no one bothered to remove them. We have to make hard choices sometimes and sacrifice some compatibility in order to ensure that we’re safe and secure with the newer technology.


Tom’s Take

Backwards compatibility is like the worst kind of nostalgia. I want the old thing but I want it on a new thing that runs faster. I want the glowing warmth of my youth but with the convenience of modern technology. It’s like buying an old sports car. Sure, you get all the look and feel of an old powerful engine. You also lose the safety features of the new body along with the comforts you’ve become accustomed to. You have to make a hard choice. Do you keep the old car original and lose out on what you like to get what you want? Or do you create some kind of hybrid that has exactly what you want and need but isn’t what you started with? It’s a tough choice to make. In the world of technology, there’s no right answer. But we need to remember that every compromise we make for performance can lead to compromises in security.


  1. I’m looking at you, OWE ↩︎