API security reduces the risk of unauthorized access to your company’s data by protecting Application Programming Interfaces (APIs), which connect software applications and the data they need to function.

Some of the most common places you’ll find APIs are connecting a web or mobile app to the data it needs to run properly.

The meaning of API Security may differ by scenario, but it is always key to a strong cybersecurity stance and acts as a first line of defense for your proprietary company data. Examples of tools used in API security include API keys, OAuth tokens, input validation, rate limiting and authentication protocols.

What is an API?

An Application Programming Interface (API) is a set of rules that lets different software systems talk to each other. Most commonlyAPIs are found between web or mobile apps and the backend servers containing the data they need to operate effectively. APIs enable software systems to exchange data, whether it’s a banking app retrieving account details or systems sharing customer data across departments. If left unprotected, APIs can expose sensitive systems to risk.

Securing APIs is a key part of any modern cybersecurity strategy, especially as businesses rely more on online services and remote access.

Why is API security important?

An API is essentially a doorway into your company’s files. Think of it as a retail showroom with one or two items on display, but most of their assets are kept in the stockroom. An API is like the badge-reader secured door between the public space and the stockroom, where only authorized personnel are allowed to facilitate the coming and going of stock.

Now substitute your company’s confidential data, and you can see why keeping your APIs secured and access to this data tightly restricted is so critical.

How API security works

API security works by restricting access to your APIs or detecting intrusions, allowing for quick mitigation in the event of suspicious activity There are several levels at which APIs can be secured, each with its own set of tools and methods for keeping your data protected.

Authentication

Authentication tells the API server that a request comes from an approved source. This can take many forms, with the most common being:

• Username and password combinations
• API keys
• OAuth token

Each method ensures that the API server knows the request is coming from a trusted and verified source and that sharing the requested data is safe.

Validation

Input validation essentially refers to checking each incoming request against a list of approved request types to be sure they’re allowed. Think of it like checking tickets for a concert; the process validates that each concertgoer has a legitimate ticket for that concert, on that night, at that venue. Input validation ensures malicious requests are stopped before they get in and wreak havoc with your data and is critical to keeping your API secure.

Authorization

Unlike authentication, authorization occurs once someone is granted access to an API server by telling the server what each user is and isn’t allowed to do once inside. Authorization errors are one of the most common ways data breaches happen.

Detection

Detection refers to monitoring real-time API traffic for unusual behavior. Machine learning can help identify patterns that may indicate a threat, such as unexpected access times or usage spikes. API detection uses ML algorithms to compare historical use patterns to what’s happening in real time to find deviations in those patterns.

Protection

API protection uses a mix of monitoring, access controls and automation to detect and block threats in real time to ensure the security of your company’s data. Monitoring activity in real time is a key part of securing your APIs.

Common API security risks

Some examples of common attack vectors involving APIs are:

• Broken authentication: When login or session controls aren’t properly secured, attackers can exploit weaknesses to impersonate users. This can include attacks like credential stuffing, exploiting a weak password policy or taking advantage of flawed session management controls
• Denial-of-Service (DoS) attacks: Attackers flood an API with traffic to overwhelm systems and disrupt service. This prevents legitimate users from accessing apps or services, often leading to outages and lost revenue
• Malicious code injection: API injection attacks are when an attacker uses lax validation protocols to insert malicious code into a system to facilitate a data breach
• Logic bugs: Even properly coded APIs can be misused. Attackers manipulate legitimate API functions in ways developers didn’t expect to gain unauthorized access or disrupt processes.
• Zero-day vulnerabilities: Zero-day exploits take advantage of previously unknown vulnerabilities to the vendor or developer, leaving them no time (0 days) to patch or defend against the intrusion

How GTT secures APIs

GTT helps secure APIs as part of a broader secure networking strategy, offering threat detection, access control and traffic visibility at the network level. Here’s how GTT can help keep your API secure:

GTT EnvisionDX API management and control

EnvisionDX provides API-enabled access to your network and security data, helping teams visualize performance, monitor usage and respond to anomalies. It supports security operations by improving visibility into network behavior, including traffic patterns that may signal misuse of exposed APIs.

Secure Access Service Edge (SASE) framework

The GTT SASE framework protects APIs through several avenues, including:

• Cloud Access Security Broker (CASB): This service includes API scanning and app detection that lets you secure real-time data.
• Firewall as a Service (FWaaS): GTT managed firewalls provide 24/7 monitoring and protection with real-time threat detection.
• DDoS protection: GTT infrastructure includes DDoS scanning centers, which provide automated detection and mitigation of DDoS attacks.

When you’re ready to have GTT design a custom security plan for your organization, reach out to our team of cybersecurity and network experts.