You’ve decided to introduce GraphQL to your organization. Great. You can look forward to the impressive flexibility and efficiency for which this query language for APIs is known.
However, while GraphQL serves a wide range of use cases, it is not without its own unique set of challenges and vulnerabilities – something we considered recently in terms of navigating the GraphQL adoption path
Today, we’re looking at specific security vulnerabilities and potential attacks you need to be aware of in relation to GraphQL, along with some essential tips on how to strengthen GraphQL API security.
Why GraphQL?
GraphQL provides some distinct advantages over REST APIs, particularly by solving issues of over- and under-fetching data. It is highly efficient in fetching data via a single request for multiple fields. This results in an enhanced developer experience and optimized performance. GraphQL is also well suited to applications like live chat and real-time feeds with real-time data updates via subscriptions.
GraphQL vulnerabilities and common attacks
As with any technology enjoying increased levels of adoption, bad actors are keen to exploit and attack GraphQL. Understanding what these attacks entail is the first step towards mitigating them.
Introspection attack
GraphQL introspection is enabled by default. This powerful feature makes it easy for developers to explore schemas—and for attackers to do the same!
Thankfully, this is an easy vulnerability to address. Simply disable introspection in production environments unless necessary.
GraphiQL
GraphiQL is the reference implementation of GraphQL’s integrated development environment (IDE). It helps you construct queries and explore schemas. However, it also provides attackers with the ability to do so.
Again, there is a quick solution. To keep your schemas secure, you can disable GraphiQL (and similar tools) in production.
Excessive errors/fields suggestions
Verbose error messages may be handy when troubleshooting, but they can also provide attackers with information they could exploit.
Put some thought into your error messages and field suggestions to ensure they don’t reveal anything they shouldn’t. Avoiding verbose error messages in production can help, as can using middleware to mask errors.
Denial of service attacks
Denial of service (DoS) attacks are nothing new, and attackers have quickly worked out multiple ways to use them to target GraphQL. These include:
- Batching attacks – where attackers aim to overwhelm servers with multiple queries in one request
- Alias overloading – this seeks to cause a high server load by repeating queries with different aliases
- Field duplication – using duplicate fields in queries to increase server workload
- Directives overloading – where attackers use multiple directives to consume significant resources
- Circular queries and fragments – these attacks aim to overload the server through the creation of infinite loops
- Pagination limit bypass – this involves the attacker manipulating pagination to retrieve excessive data
There is plenty you can do to guard against GraphQL DoS attacks. You can start by implementing query complexity limits and query validation. You can also disable or restrict batching, as well as excessive use of aliases, directives and pagination parameters, fine-tuning your approach to help guard against DoS attacks.
Injection attacks
Injection attacks are another area where common attack methods, such as SQL injection and cross-site scripting (XSS), are adapted to GraphQL.
With SQL injection, the risk is that un-sanitized inputs can allow malicious SQL code execution. With XSS, the vulnerability relates to un-sanitized input in responses, enabling attackers to execute malicious scripts.
OS command injection is another type of GraphQL injection attack to watch out for. In this type of attack, attackers take advantage of un-sanitized inputs in system commands to execute arbitrary commands.
To combat these injection attacks, validate and sanitize all inputs. To keep everything as secure as possible, use parameterized queries and implement strict access controls.
Server-side request forgery (SSRF)
Another classic attack given new life by GraphQL, SSRF, involves attackers attempting to make unauthorized internal HTTP requests. In GraphQL, this consists of manipulating queries to try and do so.
You can mitigate the risk of SSRF by validating and sanitizing URL inputs. It’s also a good idea to use allow lists for trusted domains.
Broken authentication and authorization
A risk regularly appearing in OWASP’s API Security Top 10 list of vulnerabilities, broken authentication and authorization provides opportunities for attackers targeting GraphQL. Two of the main attack vectors include:
- Authentication bypass – where attackers exploit weak authentication mechanisms
- Exploiting authorization flaws – taking advantage of insufficient access controls to get to unauthorized data
You can defend against such attacks by implementing robust authentication methods and enforcing fine-grained access controls. Remember to audit your authorization logic too regularly – this isn’t an area to set and forget!
How Tyk helps with your GraphQL security
When it comes to GraphQL, there’s plenty you can do with Tyk to keep things secure, meeting the needs of a wide range of use cases. Bearing in mind the vulnerabilities detailed above, let’s run through some Tyk features that can help.
Tyk’s schema management and security policies are a good starting point. You can configure security policies to disable introspection queries in production environments, easily reducing the risk of exposing your GraphQL schema details. This is a great way to shore up your defenses against introspection attacks.
You can also use Tyk to implement strict access control measures and combat attackers exploiting GraphiQL and similar tools. You can put access controls in place to ensure that such tools aren’t accessible in production environments unless specifically needed.
You can implement rate limiting and throttling with Tyk to reduce the risk of DoS attacks. You can limit the number of requests per user or IP address, preventing abusive usage patterns. You can also enforce depth limiting in queries, preventing excessively deep or recursive queries that can lead to circular references and DoS attacks.
If injection attacks are stressing you out, Tyk has your back there, too. You can easily implement strict input validation and sanitization rules to prevent injection attacks. Tyk also integrates nicely with backend services that sanitize and validate user inputs so you can enjoy plentiful peace of mind.
For server-side request forgery, you can use Tyk’s security policies to implement allow-lists and block-lists. This ensures that only approved domains can access GraphQL queries, neatly mitigating your risk of SSRF.
The final Tyk feature you can leverage for strict GraphQL security is our robust authentication and authorization. These mechanisms include token-based access control, as showcased in this handy video on securing your GraphQL endpoints using an authentication token. You can use OAuth and API keys too, to ensure that only authenticated and authorized users can access specific data and operations. Tyk also allows for field-based access control to any GraphQL API, meaning you can control who can access what on a very granular level – down to a single field!
Achieving robust GraphQL security
Recognizing the vulnerabilities we’ve discussed above and implementing measures to mitigate the associated risks means you can enjoy all the benefits that GraphQL delivers for modern web applications, minus the security concerns. Input validation, access control, rate limiting, and more will help you ensure everything is watertight. Just remember that regular security updates, monitoring and testing are also essential for maintaining secure GraphQL APIs!
Ready to try things out for yourself? You can sign up for a free trial of Tyk or chat with us to learn more about securing GraphQL with Tyk.
