Securely safeguarding your APIs is essential for protecting your sensitive data from unauthorized access and breaches, and your business from financial and reputational damage. This means it’s crucial to understand API security risks and how to protect against them. Read on to discover all you need to know about API security vulnerabilities and how to keep your infrastructure safe.
What are API security risks?
API security risks are vulnerabilities that hackers can exploit to access your sensitive business information. Security risks can also enable hackers to launch attacks that damage your business in other ways, such as overwhelming systems through distributed denial of service (DDoS) attacks or launching SQL injection attacks, cross-site scripting attacks or machine-in-the-middle (MITM) attacks.
The rapid evolution of the API economy has led to plentiful API security challenges in recent years. At one end of the spectrum, legacy APIs often become outdated in terms of their security, making them vulnerable to attack. At the other, API platforms that drive faster time to market mean that the push for speedy release cycles and rapid monetization often outpaces traditional forms of security testing. The API risk is further heightened by hackers embracing the latest tools and technology to make the most of zero day exploits and create entirely new attack vectors.
A robust approach to API security can help with all of this. That means understanding the nature of established and evolving API security threats and implementing measures to mitigate them.
Understanding API vulnerabilities
Solid API risk management starts with knowing how and why APIs are vulnerable. In recent years, the pace at which the API economy has evolved has contributed to the growth of API security risks. The 2024 Salt State of API Security Report shows that the count of APIs has increased by 167%, with 95% of respondents experiencing security problems in production APIs. Worryingly, despite 23% of respondents having experienced a breach, just 7.5% of organizations reported implementing testing and threat modelling programs for their APIs.
Some of the factors contributing to API security risks stem from this rapid growth. They include:
- API sprawl: Businesses have embraced the potential of APIs for both internal and external use cases. This has led to many sprawling API landscapes that have become harder to manage securely as they’ve grown.
- Personnel changes: When team members change, organizational knowledge is lost. This includes the understanding of a company’s API infrastructure and security mechanisms. The ability to mitigate security risk therefore naturally decreases as personnel change.
- Cloud adoption: With many cloud-native applications relying on APIs for their functionality, there is a broader attack surface for hackers to target.
- Flawed logic: Sometimes, the design of the API contains flaws in its logic, meaning API security issues are baked into the code.
- Easy access: The fact that many APIs are designed for public access or use by third parties again gives hackers a larger attack surface.
- Flawed integrations: Businesses often use third-party APIs, meaning they rely on the third party’s approach to security. If not carefully managed, this can introduce vulnerabilities to a business’ systems via the third party API.
Why APIs are prime targets for attacks
APIs are prime targets for attack because they provide hackers with an unprecedented wealth of opportunities to:
- Gain access to business systems: APIs connect different business systems, presenting a range of entry points for hackers who are determined to get into a company’s network.
- Steal sensitive data: Whether for sale on the dark web, to hold a business to ransom or for any other nefarious purpose, hackers regularly attempt to steal sensitive business data. API data security vulnerabilities can make this easier for hackers to achieve.
- Disrupt operations: DDoS and other malicious attacks can be costly to businesses in terms of operational disruption and the time it takes to restore everything to proper working order. Hackers with disruption in mind therefore often seek out API security vulnerabilities in order to target specific companies.
- Damage businesses’ reputations: Customer trust is hard won and easily lost. API security risks that enable hackers to carry out attacks that damage a business’ reputation can therefore have long-lasting consequences.
Impact on business operations
Successful API security attacks can have a major impact on business operations. They are costly in terms of the time and resources they take to investigate and rectify, and they distract from regular business operations. API security issues can also lead to loss of consumer trust, damage to commercial partnerships and regulatory headaches that include additional oversight, fines and other penalties.
With this in mind, the need to understand API security risks and put mitigation measures in place becomes paramount.
Top API security threats
OWASP regularly reviews the top 10 API security risks that businesses face, supporting all those involved in implementing API risk management processes to understand the latest threats.
In 2023, OWASP’s top 10 API security risks included:
- Broken object-level authorization
- Broken authentication
- Broken object property-level authorization
- Unrestricted resource consumption
- Broken function level authorization
- Unrestricted access to sensitive business flows
- Server side request forgery
- Security misconfiguration
- Improper inventory management
- Unsafe consumption of APIs
While this is not a full list of every possible security risk, it provides an excellent starting point for businesses looking to grow their knowledge of ways in which they might be vulnerable to API security attacks.
Let’s take a look at some of these vulnerabilities in more detail and discuss what you can do to mitigate the security risks they pose.
Broken object-level authorization (BOLA)
The risk: Objects are collections of data. Developers use them for rapid information access. This means that hackers can too, if object-level authorization isn’t implemented correctly.
The mitigation strategy: Security teams need to ensure that authorization checks are in place for every API endpoint and ensure that consumers have the minimum level of access necessary to achieve what they need. The use of indirect object references rather than direct database references can also help mitigate this API risk.
Broken authentication
The risk: API authentication verifies a user’s identity and grants them access. If authentication mechanisms are broken, for example by incorrect implementation, they can enable hackers to assume users’ identities.
The mitigation strategy: Businesses have numerous processes at their disposal when it comes to implementing secure authentication processes. Biometric authentication, which uses fingerprints, faces, palm prints, voices or other biological or behavioural features, has become a popular means of beefing up authentication processes in recent years. Many businesses have also adopted multi-factor authentication for enhanced API security. Continuous authentication and password-less authentication can also help mitigate this threat.
Excessive data exposure
The risk: APIs that return sensitive data to clients (by design, with the intention of the data being filtered by the client) can be exploited by hackers who sniff the traffic and see the sensitive data.
The mitigation strategy: Security teams need to ensure authorization is implemented correctly at the object property-level.
Unrestricted resource consumption
The risk: If the resources that APIs rely on are fully consumed, the APIs will no longer be able to service requests, potentially including those already in progress. This is what happens when DDoS attacks take place.
The mitigation strategy: Businesses can use a range of measures to guard against unrestricted resource consumption, including circuit breakers, payload size limiting, rate limiting/throttling, caching, enforced timeouts and IP restriction. To address resource consumption in relation to GraphQL security issues, query complexity limiting is essential.
DDoS attacks
The risk: DDoS attacks, as we mentioned above, can quickly overwhelm an API. They have the power to bring services, servers and entire networks crashing down, with hackers using botnets to overwhelm their targets. Hackers build botnets using compromised computers, servers, IoT devices and the like – or simply buy into using an existing botnet on the dark web. Each of the bots in the network then sends a request to the target API, overwhelming its resources.
The mitigation strategy: API gateways can help defend against DDoS attacks through advanced approaches to rate limiting, circuit breaking, security policy enforcement, monitoring and more. Businesses can also use specialist cloud-based and AI-based tools to defend against DDoS attacks.
Injection attacks
The risk: These attacks involve injecting malicious input into a webpage or app, which then acts on the input as though it were legitimate. The effects of this can be wide-ranging; hackers commonly use injection attacks such as SQL injections and cross-site scripting to run malicious code, break user permissions and access sensitive data.
The mitigation strategy: There are numerous ways that you can defend against injection attacks. Implementing runtime API security can help head off these types of API security attacks in real-time, while input sanitization can further bolster your defences. Other mitigation measures may include the use of parameterized queries, content security policies and schema validation, depending on the nature of your API architecture.
Broken function-level authorization
The risk: Authorization flaws can leave APIs open to attack, giving hackers access to administrative functions and resources.
The mitigation strategy: Taking a structured, well-implemented approach to access control, with a clear separation of administrative and regular functions, is key to mitigating this API security risk. You can use path-based access rights, allowlists, blocklists and cross-origin resource sharing (CORS) as part of a robust defense to mitigate security risk in this area.
Unrestricted access to sensitive business flows
The risk: When hackers understand an API’s business model, they can identify sensitive business flows and automate unauthorized access to them. This puts them in a powerful position to disrupt business operations.
The mitigation strategy: This type of attack is unique to an API’s backend systems and processes. As such, regular security testing is essential, along with protecting your endpoints using robust authentication and authorization. Splitting admin APIs from client-facing APIs and implementing different governance models for them can also serve you well here.
Server side request forgery
The risk: Server side request forgery sees the attacker manipulating a server so they can make unauthorized requests for resources. This can lead to data leaks and enable remote code execution.
The mitigation strategy: An API gateway can help defend against server side request forgery through JSON schema validation for incoming payloads, which can be used to reject suspicious requests (such as localhost URLs, which hackers can use to perform port scanning).
Security misconfiguration
The risk: Configuring API security can be complex. Failure to follow best practices in doing so can open the door to hackers.
The mitigation strategy: Implementing security at gateway level can help you protect against these types of API security risks. You can use TLS, mTLS, response header and response body manipulation, error templates, CORS functionality, environment variables, policy path-based permissions and third party secret storage as part of a solid mitigation approach. If you work with GraphQL APIs, you can also implement schema introspection and schema validation to further shore up your defenses.
Improper asset management
The risk: Failing to maintain a proper inventory of your API assets and endpoints can result in forgotten and improperly deprecated API versions providing hackers with a route into your systems.
The mitigation strategy: There are various approaches that can help you manage your API inventory and assets properly. A developer portal integrated with a configuration management database can work well, as can a strategic approach to using analytics and monitoring to identify stagnant and stale APIs. A considered approach to versioning is important, with sunsetting to ensure that older API versions become inaccessible. API key and API token rotation are also helpful in ensuring proper asset management.
Unsafe consumption of APIs
The risk: As we mentioned above, the use of third party APIs exposes businesses to additional security risks, heightening the potential for API data security breaches, injection attacks, DDoS attacks and more.
The mitigation strategy: Using an API gateway as a forwarding proxy to third party APIs can help here. It enables you to use TLS to encrypt traffic and ensure clients use the right service, implement JSON schema validation and take a clear approach to versioning.
Essential API security technologies
Protecting against API security threats becomes easier when you embrace the right tools and technologies as part of your approach. We’ll run through a few ideas here, showing how you can use these to build a strategy that defends your business from common and emerging API security risks.
OAuth and authentication
Using OAuth 2.0 to protect your APIs is an excellent starting point. Doing so delivers multiple security benefits, including:
- Centralized user authentication: You can easily integrate OAuth with a central identity provider, meaning you can use a single system to control authentication and better protect user data.
- Separate authentication and access: OAuth limits the exposure of credentials through the separation of concerns, keeping user authentication apart from granting access to resources.
- Efficient token management: Tokens play a fundamental role in API security. They enable you to grant time-limited access to your APIs, apps and services. OAuth security tokens also help with managing user data, including in relation to authorization protocols for read and write access. The fact that it is easy to quickly revoke compromised tokens is also helpful in addressing API security challenges.
- Optimized flows: By enabling a simplified developer experienced through optimized authorization flows, OAuth can further boost API security.
- Multi-user efficiency: If you need to support a large volume of users, OAuth may provide a more suitable alternative to the use of API keys.
API gateways
API gateways can be hugely helpful with everything from fine-tuning API performance to achieving seamless API compliance. When it comes to API security risks, a gateway can do much to defend your infrastructure. It can provide the golden path and guardrails you need for enhanced security while also supporting accelerated innovation.
If you’re currently seeking an API gateway to help with your API security, be sure to look for one that works with all API protocols. This means that, whether you need a secure REST API, a well-protected GraphQL environment, secure async APIs or even well-defended SOAP APIs, you can implement all the security you need with a single API gateway solution.
With an API gateway in place, you can protect against API security risks by implementing measures such as:
- Key hashing: This can help obfuscate your API keys.
- TLS and SSL: You can use these to encrypt data in transit. They are also important for authentication handshakes between clients and servers, validating servers’ identity and confirming data integrity.
- Trusted certificates: You can use your API gateway to create a list of trusted certificates as part of using mTLS.
- Certificate pinning: This protects against upstream certificate compromise by only allowing specified public keys used to generate certificates.
- Flexible API security: You can use your API gateway to secure your APIs using bearer tokens, JSON Web Tokens, HMAC, multi-chained authentication, OAuth 2.0 and OpenID Connect. This flexibility provides the ability to implement the ideal API security arrangements for your particular environment.
- Security policies: Using an API gateway such as Tyk empowers you to implement API management policies that incorporate a range of security options and apply these to an API key. Examples include partitioned policies and method and path policies.
Implementing security at the gateway level in this way helps deliver a standardized approach, supporting enhanced API security across your business.
Data encryption
We mentioned using TLS to encrypt data in transit. This is a crucial element of your API security approach. Encrypting data in transit protects against multiple API security risks, keeping your data safe from eavesdropping, tampering and MITM attacks.
Token management
API tokens grant users certain permissions. It is therefore important to manage tokens carefully to ensure they are not compromised (and to swiftly revoke any tokens that are compromised). This includes the need to protect them in storage and in transit and to take a considered approach to expiration limits.
Rate limiting and throttling
Rate limiting and throttling are an essential means of protecting your APIs and upstream services from being overwhelmed by requests. This supports reliable performance and fair usage, as well as serving as a defense against DDoS attacks. You can configure rate-limits at API-level and key-level to meet the needs of different use cases, protecting your upstream services from becoming overloaded whilst also providing granular control for managing API client access.
Zero-trust framework
A zero-trust framework assumes that no request is to be trusted, irrespective of where the request originates. It is a security concept that spans the cloud, on-premise and hybrid environments.
Zero-trust means that every user has to be continuously authenticated and authorized. The idea is that this makes it harder for hackers who have exploited a single system vulnerability to use that exploit to gain further access.
API testing tools
Key to any API security approach is regular testing. You can combine manual pen testing with automated tests for best use of your resources and for maximum defense. Remember to update your testing strategy and tools regularly to account for emerging API security risks and ensure you don’t get caught out by evolving threats.
Advanced API protection strategies
If API security risks are keeping you awake at night, there is plenty you can do to elevate your approach and ensure your APIs are well defended. Let’s look at a few of your options.
Service mesh security
Implementing a service mesh comes with a range of benefits in terms of your API protection. It can help you implement a zero-trust framework, along with advanced traffic management capabilities, security policy management, mTLS encryption and tight access control, all without the need to make changes to your underlying code.
Threat modeling
API security threat modelling supports you to see the bigger picture in terms of the API security risks that your business may be facing. It provides a way for you to identify risks and evaluate the danger they pose, so that you can put appropriate mitigation measures in place to counter them. Threat modelling can be useful in identifying API design flaws and spotting potential API security issues at an early stage, supporting a preemptive and carefully targeted approach to API protection.
Continuous security assessment
API security threats evolve continuously. So should your approach to assessing and dealing with API security risks. This calls for regular manual pen tests and automated tests, as well as processes to ensure your teams frequently grow their knowledge of traditional and emerging API security risks. Having them read this article is a great starting point!
API inventory management
Maintaining an inventory of your APIs ensures nothing ‘slips through the cracks’ and puts your data at risk without your realizing it. Inventory management ensures you have a full picture of your API ecosystem. This guards against personnel changes leading to stagnant and stale APIs slipping from the corporate memory banks and eventually becoming vulnerable to attack due to their outdated security.
Incident response planning
While no business likes to dwell overly long on the prospect of an API security breach occurring, incident response planning is important. You can use it to map out the processes that would take place in the event of an API security incident occurring. The processes can take into account a variety of different incidents, providing a structured approach in response to each. It can do much to ensure the continued availability of other services and to minimize disruption in the event of an API security attack.
Incident response planning for API security risks means that, if some kind of breach is attempted or does occur, your reaction to it will be calm, considered and strategic – not a panicked response that could end up doing further damage.
Putting thought into incident response planning is a key preventative measure when it comes to protecting your business from API security threats and the impact that any successful attacks could have.
Conclusion
We’ve seen from the API security risks and mitigation measures above just how wide-reaching your security strategy needs to be if it is to provide solid protection. Gaining this knowledge is the first step towards achieving that protection and ensuring that your APIs, data and services are secure.
From the top 10 API security threats listed by OWASP to emerging challenges that take advantage of zero day exploits, hackers can come at your APIs from all directions. The more prepared you can be for their attacks, the more likely you are to defend against them successfully. Doing so can:
- Keep your data safe
- Protect the performance of your APIs, apps and services
- Avoid damage to customer trust and thus prevent churn
- Protect your business reputation
- Prevent financial loss
- Avoid regulatory penalties
Next steps
Ready for more API security info? Then our API testing tools article is a great next step. We look at how testing tools can help ensure a robust defense against API security risks, as well as assuring you that your APIs all work and perform as you expect them to.
