API Security: Why Your Legacy WAF Is No Longer Enough

Why API Security Is Different from Web Security

Today, APIs carry 83% of all web traffic (Cloudflare 2024). Yet most firms still guard them with a WAF built for web pages. Clearly, that is a big gap. API security is not the same as web page security. In fact, the threats are different. Also, the attack methods are different. So the tools you need are different too.

In short, a WAF checks for things like SQL attack code and cross-site scripting. In short, these are web page attacks. But APIs face a whole other set of risks. Then there are broken login checks. Also, leaked data fields. And abuse of app logic. A WAF can’t catch these because it doesn’t know how your API works. So your API security depends on tools built for APIs — not web pages.

This guide shows you the 5 attacks your WAF misses. It also covers the OWASP API Top 10 in plain words. And it gives you a checklist to fix each gap.

How APIs Differ from Web Pages

Basically, a web page sends HTML to a browser. Then a user clicks buttons. So the WAF watches that traffic. But an API sends raw data between systems. There is no browser. And there are no clicks. Instead, it is just code talking to code. So the WAF rules that work for web pages don’t apply to API calls.

Also, APIs expose more data than web pages. For example, a web page shows one customer’s name. But an API call might return 10,000 records if the access check is weak. This is why API security needs its own controls.

What Your WAF Misses — 5 API Security Attacks WAF Cannot Stop

Your WAF is good at what it does. But it was not built for API security. Below are 5 common API attacks that your WAF will miss.

WAF vs API Security: A Side-by-Side Look

Here is a clear view of what a WAF covers and what it misses for API security.

The OWASP API Security Top 10 in Plain English

OWASP (Open Web App Security Project) put out a list of the top 10 API risks. But most write-ups are very technical. Here is each one in simple terms.

1. Broken Object Access (BOLA): Users can see other users’ data by changing an ID in the API call.
2. Weak Login Flows: Poor auth lets attackers steal or guess access tokens.
3. Object Property Abuse: The API lets users change fields they shouldn’t — like their own role or price.
4. No Resource Limits: No cap on API calls. So attackers can flood or scrape at will.
5. Missing Function Checks: Normal users can call admin-only API routes.
6. Server-Side Request Forgery: The API is tricked into calling private internal services.
7. Bad Security Setup: Missing headers, open CORS, debug mode left on in live systems.
8. No Input Checks: The API accepts bad or risky data without checking it first.
9. Poor Asset Management: Old or test APIs left live in live systems — nobody knows they exist.
10. Unsafe API Use: Your API trusts data from other APIs without checking it.

Shadow APIs: The Biggest API Security Risk You Can’t See

Shadow APIs are APIs that run in live but nobody on the security team knows about. In fact, Salt Security found that 30% of APIs in a average firm are unknown to the security team. These are old test APIs, forgotten beta routes, or APIs built by a team that left.

Why Shadow APIs Are So Dangerous

Obviously, you can’t protect what you don’t know about. So shadow APIs have no WAF rules, no rate limits, no login checks, and no watching. As a result, they are wide open. So attackers find them fast using simple API scanning tools.

How to Find Shadow APIs

First, run an API search scan across all your traffic. Then match what you find against your API docs. The gap between the two is your shadow API risk. Also, check old staging and test sites — they often have live APIs that were never shut down.

An API Security Checklist for Business Teams

Below is a simple API security checklist. Use it to find and fix the most common gaps in your API security setup.

1. Map all your APIs. Find every API in production — known and unknown. You can’t guard what you can’t see.
2. Add auth to every endpoint. No API should be open without a login check. Use OAuth 2.0 or API keys at minimum.
3. Check access on every call. Don’t just check “is this user logged in.” Also check “can this user see this data.” This stops BOLA.
4. Set rate limits per endpoint. Cap how many calls one user or IP can make per minute. This stops scraping and floods.
5. Cut extra fields from replies. Only return the data the app needs. Don’t send full records when the app shows a summary.
6. Test APIs before go-live. Run OWASP API Top 10 tests in your CI/CD build process. Catch flaws before they reach production.
7. Monitor API traffic at live. Use live API security tools that watch live traffic for abuse patterns — not just known attack known patterns.

How Signisys Delivers API Security for Enterprise

Specifically, Signisys helps firms find, test, and protect every API in their estate. Here is how the service works.

API Discovery and Risk Mapping

First, we scan all your traffic to find every API — known and shadow. Then we map each one to the OWASP API Top 10 risks. So you get a clear picture of where your gaps are and which ones to fix first.

API Security Testing

Next, we run tests against every API for BOLA, broken auth, data leaks, and rate limit flaws. Also, we test both live APIs and CI/CD pipeline builds. So flaws are caught before they reach production.

Managed WAAP with API Protection

Signisys deploys cloud-based WAAP that covers both web pages and APIs. This includes runtime API watch tools, bot defence, rate limits per endpoint, and format checks. Also, all controls map to RBI API guidelines and DPDP Act needs. So audit-ready proof comes built in.

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