API Security: Why APIs Are the New Attack Surface

Every mobile app, cloud service, and integration your organization runs talks to something else through an API. Those connections now carry more traffic than human users ever did. Attackers noticed first. In 2025, 87 percent of organizations reported an API security incident, and the average business faced 258 API attacks a day. The interfaces built to connect your systems have become the front door intruders knock on most.

An API, or application programming interface, lets two pieces of software exchange data and instructions. Your banking app checks your balance through an API. Your payroll system pushes records to the tax agency through an API. Modern software runs on thousands of these links. Each one exposes a slice of your logic and your data to the outside world. Secure them well and your systems work together safely. Leave them exposed and you hand an attacker a direct path to your records.

Why APIs Draw So Much Attack Traffic

APIs skip the parts of a website a person sees. No login screen slows an attacker down. No form gets in the way. An API returns raw data to whoever asks the right way. Akamai’s 2026 State of the Internet report found daily API attacks per organization rose 113 percent year over year, from 121 to 258. The same report found the typical organization runs around 3,000 APIs holding sensitive data, and 12 percent of them carry a known weakness. Attackers scan for these gaps around the clock because the payoff sits right behind the interface.

The Most Common API Weaknesses

The OWASP API Security Top 10 ranks the flaws you meet most often. Broken object level authorization tops the list. It happens when an API trusts a user to request only their own records but never checks the request. Change one number in the request and you read someone else’s data. Broken authentication sits second, where weak token handling lets an attacker pose as a real user. Security misconfiguration, unrestricted resource use, and poor inventory of forgotten endpoints fill out the rest. Most of these failures trace back to access control the developer assumed the client would respect.

What Canadian Guidance Recommends

The Government of Canada treats API security as a design requirement, not an afterthought. Treasury Board’s guidance on API gateways states security should stay top of mind in any API implementation. It requires internet-facing APIs to sit behind a gateway rather than rely on IP whitelists. The gateway authenticates every request before it reaches your backend, throttles traffic to stop abuse, scans content for malicious payloads, and logs each call with the caller’s identity. The guidance also tells teams to flag suspicious patterns, such as one API key arriving from many locations at once.

These controls line up with the wider Canadian approach. The Canadian Centre for Cyber Security and its Baseline Cyber Security Controls for small and medium organizations both stress access control, logging, and least privilege. Under PIPEDA, an API leaking customer personal information becomes a reportable breach with real legal weight. For federal teams, ITSG-33 builds identification, authentication, and access control into its control catalogue, giving public sector developers a standard to measure their APIs against. The result is a clear expectation across Canadian organizations of every size: an exposed API without access control, logging, and rate limiting fails to meet the baseline.

How to Secure Your APIs

Start with an inventory. You protect only the APIs you know about. Forgotten and undocumented endpoints, often called shadow APIs, cause a large share of incidents. Map every interface, then enforce strong authentication on each one. Apply least privilege so a token reaches only the data its owner needs. Add rate limiting to blunt automated abuse and volumetric attacks. Validate every input against a strict schema and reject the rest. Log all access and review the logs for the odd patterns Canadian guidance calls out. Test before you ship, and test again after every change. Give each of these steps a named owner so nothing slips between the development team and the security team.

The Skills Behind Secure APIs

Securing an API takes people who understand how software talks and how attackers listen. Developers need secure coding skills built for web and API work. The Certified Secure Web Application Engineer program teaches how to design authentication, authorization, and input handling so the flaws above never ship. The Certified Web Security Engineer track goes deeper into hardening the web and API layer against real attack methods.

On the offensive side, you need someone who tests APIs the way an attacker probes them. The Certified Penetration Testing Engineer certification builds the hands-on skills to find broken authorization and injection flaws before an outsider does. Once your APIs run in production, a monitoring team watches for abuse. The Certified Cybersecurity Analyst program prepares analysts to read access logs and spot the behaviour-based attacks now driving most API incidents. Tools help, but trained people close the gap between an exposed interface and a secured one.