What Are APIs and Why Do They Pose Risks?

Think of APIs (Application Programming Interfaces) as digital translators. They let different systems talk to each other, from your CRM sending customer data to your invoicing system, to your cloud apps connecting with external platforms.

The risks come in because:

• APIs often handle sensitive data.
• They’re exposed to the internet by design.
• Developers sometimes prioritise functionality over security.
• APIs can get forgotten (“Zombie APIs”) and left unmonitored.

Combine those factors and you’ve got one of the biggest modern cybersecurity blind spots.

Common API Security Risks Businesses Face

Here’s where things get serious. Some of the most common API security risks include:

• Weak Authentication & Authorisation – APIs without proper access controls can expose sensitive data.
• Unencrypted Traffic – Data passed in plain text can be intercepted.
• Excessive Data Exposure – APIs often return more data than needed, which can be exploited.
• Lack of Rate Limiting – Attackers can flood APIs with requests, leading to denial-of-service.
• Forgotten APIs (Zombie APIs) – Old, unused APIs that still exist in your systems and create hidden risks.
• Insufficient Logging & Monitoring – Attacks often go unnoticed because API traffic isn’t watched closely.

Each of these risks creates a direct path for cybercriminals to exploit.

Real-World Examples of API Breaches

APIs have been at the centre of some of the biggest recent data breaches:

• Facebook (2019) – An API bug exposed millions of user phone numbers.
• Parler (2021) – Poor API security allowed attackers to scrape public and private posts before the platform was taken offline.
• T-Mobile (2022) – An unprotected API exposed sensitive customer information.

These aren’t just “big company problems.” SMEs face the same threats but often lack the security budgets and dedicated teams to fight back.

Step-by-Step Guide to Building API Security into Your IT Checklist

If you want to secure your IT properly, APIs must be part of your wider IT checklist. Here’s a step-by-step approach:

• Identify all APIs – Create an inventory. You can’t protect what you don’t know exists.
• Classify by sensitivity – Not all APIs are equal. APIs handling payment or personal data need higher protection.
• Apply authentication & authorisation – Use OAuth 2.0, API keys, or tokens. Never leave APIs open.
• Encrypt all traffic – Force HTTPS/TLS encryption.
• Enable logging & monitoring – Watch for unusual traffic patterns.
• Apply rate limiting & throttling – Stop brute force attacks by limiting requests.
• Review & retire old APIs – Audit regularly to avoid Zombie APIs.

API Security Best Practices for SMEs

Here are actionable practices for smaller businesses:

• Shift Left – Involve security during development, not after.
• Use API Gateways – Centralise access, apply consistent policies.
• Test Regularly – Penetration tests and vulnerability scans are vital.
• Document Everything – Clear documentation prevents “shadow APIs” from sneaking in.
• Educate Staff – Train developers and IT teams on secure coding and API security standards.

How APIs Fit into Cloud and Hybrid IT

Cloud adoption and hybrid IT setups depend heavily on APIs. Every cloud service you use — Microsoft 365, Azure, AWS — connects through APIs. That means your cloud security strategy is incomplete without API security.

When moving towards a hybrid IT setup, businesses often overlook the security of the “glue” that connects on-premise and cloud systems. Attackers don’t.

Checklist: Secure API Management in 2025

Here’s a quick API security checklist you can download and use:

• ✅ Inventory all APIs (internal & external).
• ✅ Use authentication and authorisation.
• ✅ Encrypt all API traffic.
• ✅ Apply rate limits.
• ✅ Monitor and log API activity.
• ✅ Review regularly for Zombie APIs.
• ✅ Securely retire unused APIs.
• ✅ Educate staff on API risks.