SOA vs. Microservices – The Cyber Security Overview

Service-oriented architecture and microservices have a lot of similarities – but pose different cybersecurity risks. You have to be smart about which one you choose since your architectural approach will be the bridge between customers and your company. So, what’s the difference between SOA and microservices in cybersecurity?

SOA and microservices architecture differ in age, costs, and possible risks. Microservices may leave a lot of access points wide open, while SOA could compromise multiple apps from within. Vulnerability scans and penetration tests are the best way to ensure no exploits are left in the infrastructure.

Did you know SOA is ten years younger than microservices? That pushes startups to choose the second option, though large companies are juggling between both choices. Learning the differences between each other (and their risks) is a must to make the right choice.

What’s the Difference Between SOA and Microservices?

Service-oriented architecture (SOA for short) and microservices have a lot of similarities and a few differences. The main thing that sets them apart is their functionality.

In SOA, components are reused or shared between apps. That means developers take parts from one app to use it in another all the time. It’s the oldest way of doing things.

In microservices, each part works individually – but complements each other. In other words, it has a lot of small moving parts that create a whole system of sorts.

Both approaches have cybersecurity advantages and disadvantages.

Do People Still Use SOA?

Absolutely! Large companies still use service-oriented architecture. At the same time, small startups prefer microservices because it’s a more cost-effective approach.

Nevertheless, that doesn’t mean all large companies choose to go down the SOA route. In fact, certain tech giants, such as Amazon, have deployed a microservice architecture for their businesses.

Does that mean SOA is obsolete? Far from it! However, as time goes on, we may see more companies adopt a microservice architectural approach.

The question is: will they do it because of efficiency, costs, or vulnerabilities?

Is SOA Vulnerable?

Service-oriented architecture isn’t inherently vulnerable, though it’s far from bulletproof. Then again, no app, framework, or architecture design is invulnerable, especially when hackers are always working to create new attacks.

Can you find vulnerabilities in SOA? Absolutely! Can you create something that follows SOA principles that’s almost invulnerable? You can!

So, what does that mean? It means you have to put in the effort to have strong defenses, no matter the architectural design you choose. At the same time, if you pick service-oriented architecture, you need to be aware of its risks.

The Risks of Service-Oriented Architecture

1. A Small Mistake Could Be Huge

Service-oriented architecture presents a feature that’s both advantageous and risky at the same time: it reuses components throughout applications. In other words, developers take parts from one app and use them in another.

How is that an issue? Well, imagine that a small part a developer borrowed for another app is vulnerable. That means one hacker can compromise multiple parts of your architecture in one swift blow, which wouldn’t happen if you were able to isolate each part (as you can with microservices).

Of course, that doesn’t mean every time you borrow a small piece of code or component from one app and use it in another, you’ll expose yourself to an attack – but doing so increases the chances of it happening.

2. Vulnerable to Common Attacks

Service-oriented architecture has been around for a long time, meaning we know a lot about how to attack it (and, fortunately, how to defend it). Injection attacks are a common way of going against SOA, and DDoS attacks are a great way to shut it down and wreak havoc for a while.

Does that mean microservices are invulnerable to attacks? Absolutely not! However, SOA has been around for over two decades, giving us a long list of attacks we can use (or at least attempt) if we want to steal information from (or simply bother) a business.

3. Requires a Large Investment

One of the biggest issues with SOA, especially for startups, is upfront costs. SOA is costlier than microservices, which may push you away from the idea of adopting this architectural design.

More often than not, SOA is referred to as the option large companies prefer. It has to do with a lot of things (such as the way service-oriented architecture is by design), though you can’t leave money out of that discussion.

So, how is being costlier a vulnerability? Simple! Companies want to make as big of a profit as possible – and sometimes, that means cutting costs in certain areas. Spending less money than necessary in IT leads to vulnerabilities – and having a small budget for an SOA project could leave you exposed in the long run.

4. Old Way of Doing Business

Service Oriented Architecture was huge during the 2000s. Nothing lasts long in tech, so a decade-long reign is nothing to laugh at. In fact, a lot of companies still use SOA today.

Unfortunately, old ways of doing things tend to be vulnerable. Even worse, they have well-known vulnerabilities hackers love to exploit. Sometimes, these issues go unpatched for years – and the longer it takes for developers to deal with an issue, the likelier it is for them to never take care of it.

We love those who can handle old architecture without trouble. We also recognize most prefer to use new and efficient ways of handling their business, like microservices.

How Secure Are Microservices?

Microservices are very secure. In fact, companies like Netflix and Paypal use them. Of course, it all boils down to how you design and create your infrastructure – as well as how you maintain it.

Cybersecurity is about prevention and reaction. Microservices security is no different. In other words, you have to structure your app to mitigate the chance of an attack and defend yourself when they take place.

How can you accomplish that? Follow cybersecurity best practices, routinely scan for vulnerabilities, and perform penetration tests to see how hackers would attack you. At the same time, learn about the top risks of microservices.

5 Microservices Risks

1. The Infrastructure Is Spread Thin

The way you’ll handle infrastructure is one of the biggest risks if you go down this route.

Simply put, you have one too many places you have to take care of: servers, cloud providers, and more. You have to do it that way since the whole point of microservices is handling different needs as efficiently as possible.

Unfortunately, that leaves you open for attacks in multiple areas. Dealing with each one costs money and time. What’s the worst part? Your cybersecurity department will probably overlook one – because they have to deal with a lot of them!

2. Too Much Exposure Between Channels

You already know how microservices work: too many things in too many places working at the same time. Of course, that has many advantages: it’s easier to scale, more efficient, and affordable.

Does it have any cons? Absolutely. Microservices are (as the name suggests) a bunch of small components working together. In other words, you have a lot of moving parts working with one another – and threat actors love to slip through the cracks.

That’s not all: scanning for vulnerabilities is a must – but even the best in business forget about certain areas, such as cross-service communication. That often happens because that part seems small enough not to care for. However, hackers thrive when you start to overlook things.

3. One Too Many Access Points

As you know, microservices are full of small components interacting with each other. That’s the main gist of it all – and it’s also the root cause of most of the problems.

Since you have a lot of small components working together, you also have a lot of access points. Most of them will be legit: those customers and employees use. Unfortunately, some will be harmful – the kind of thing hackers love.

You’re bound to have trouble unless you can bottleneck interactions through one access point. Fortunately, we have the answer to that at the bottom of our article.

4. Data Is Located in Multiple Places

Microservices force your hand to store data in multiple places. Once again, you have many small components interacting with each other. Most of the time, each component has a set of data that may or may not be stored in another component too.

In other words, you have similar information in different places at once. That’s great if you’re thinking about backups and having access to data 24/7.

At the same time, that very same practice could turn into a vulnerability: everywhere you store data is susceptible to a data leak. You’re facing a liability unless you’re confident nothing will happen at each cloud storage or server you have.

5. The Everchanging Landscape

One of the biggest advantages microservices present is scalability. Working with small components means you can upgrade one of them without altering the others.

That presents an opportunity to move as fast as technology advances. In other words, you adapt to the everchanging tech landscape better than the competition.

It also means you’re more susceptible to attacks. The more you change, the more vulnerabilities you could leave wide open. Of course, that’s not always the case – but it’s always a possibility.

Fortunately, you can mitigate that issue by following microservices best practices.

Microservices Best Practices

  • Isolate Each Part. Microservices use multiple parts to create a system. These parts need to work together to ensure you have a smooth ride. However, they don’t need to rely on each other all the time: you need to make sure you can isolate each part up to the point of being able to modify them without altering the course. Isolation also prevents attacks and leaks from continuing if one part is compromised.
  • Bottleneck Access With an API Getaway. We told you about different access points (that could be legitimate or illegitimate). What’s the best way to deal with that? Bottleneck access using an API getaway. Your API getaway will be the main entry point for all requests, which will authenticate and authorize users – or not, keeping everything safe and sound.
  • Limit Permissions. Each user and bot should have limited access to each component. In fact, you should limit permissions and authorization levels by default. Otherwise, hackers will exploit that vulnerability and perform an attack, such as privilege escalation.
  • No Sensitive Plain Text. Storing sensitive data as plain text, especially passwords, is never a good idea. Encryption is easy to use and very hard to crack, so make the most of it – even if you believe your app will be for employees only (because they’re also targets).

Is SOA or Microservices More Secure?

That depends on who you ask! Service-oriented architecture and microservices are similar, though they have different sticking points. You could make a broad generalization and see the debate as an old vs. new thing.

What does that mean? Well, SOA is the old way of doing things. It started around the early 2000s. In cybersecurity, old is seen as bad and vulnerable – but that’s not always the case. We know the vulnerabilities around service-oriented architecture, which could help you prepare your defenses better. At the same time, it helps hackers know where to attack.

In contrast, microservices are the new way of doing things. It started in the 2010s. Does that mean microservices are bulletproof? Well, far from it. However, it’s supposed to be one step above SOA in everything, including security. However, new things tend to have vulnerabilities we’re unaware of, so constant surveillance and scans may be necessary to prevent issues.


We at U.S. Cybersecurity realize both SOA and Microservices present advantages and disadvantages. Although most companies choose a microservices-related approach, there’s still a place for service-oriented architecture. The important part is not which one you choose but rather how you’re going to prepare your company’s cybersecurity to fend off any attacks – since both methods have certain vulnerabilities hackers could exploit.

Herman McCargo

Herman is a Microsoft Certified Security Engineer and Cybersecurity Specialist. He’s been in the technology field for over 20 years and has expertise working with the most critical technology infrastructures. He has a deep understanding of cyber risks, threat mitigation and prevention, and overseeing infrastructure.