Web Application Vulnerability Scanner: Code-Level Protection
Written by the Rafter Team
A web application vulnerability scanner tests your application for the security flaws that attackers actually exploit — injection, broken access control, authentication bypasses, cross-site scripting, and the rest of the OWASP Top 10. Traditional scanners probe running applications from the outside. Code-level scanners find the same vulnerability classes in your source before the application is ever deployed. The strongest approach uses both, but code-level scanning gives you the earliest possible feedback loop.
Every web application vulnerability found in code is one that never reaches a production URL.
Scan your web application code with Rafter — findings in your pull request, not your incident log.
How Web Application Vulnerability Scanners Work
Web application scanners fall into two categories based on when they run:
Dynamic scanners (DAST) interact with your running application. They send crafted requests — malformed parameters, injection payloads, authentication bypass attempts — and analyze the responses. OWASP ZAP and Burp Suite are the standard tools here. They find what's exploitable right now, but they require a running environment and can only test endpoints they can reach.
Static scanners (SAST) analyze your source code without running it. They parse your codebase, build data flow graphs, and trace user input from HTTP handlers through business logic to database queries, file operations, and HTML output. They find vulnerabilities that exist in code even if no test case exercises the specific path.
SAST catches flaws earlier and cheaper. DAST confirms exploitability. For web applications, the highest-value investment is shifting scanning left into your development workflow.
What a Web Application Vulnerability Scanner Finds
The vulnerability classes that matter most for web applications map directly to the OWASP Top 10:
- Injection — SQL, NoSQL, OS command, and LDAP injection where request parameters reach interpreters without sanitization
- Broken access control — missing authorization checks, insecure direct object references, privilege escalation paths
- Cross-site scripting — reflected, stored, and DOM-based XSS where user data renders in HTML without encoding
- Security misconfiguration — verbose error messages, default credentials, unnecessary HTTP methods enabled
- Server-side request forgery — user-controlled URLs passed to internal HTTP clients without validation
- Insecure deserialization — untrusted data deserialized into objects that trigger code execution
Broken access control has been the number-one OWASP finding since 2021. Automated scanners catch the pattern — missing auth middleware on protected routes — but only if they analyze the code paths, not just the HTTP responses.
Code-Level Scanning for Web Applications
Runtime scanners miss what they can't reach. If an endpoint exists in your code but isn't linked from the UI, a crawler-based DAST tool may never test it. An attacker reading your JavaScript bundle or API documentation will find it immediately.
Code-level scanning has no blind spots from incomplete crawling. It analyzes every route, every handler, every middleware chain in your codebase. It detects vulnerabilities in code paths that are rarely exercised — error handlers, admin endpoints, batch processing jobs — where security oversights are most common.
Rafter runs code-level scanning on every commit to your web application repository. It maps data flows from HTTP request parsing through your application layers to the sinks where vulnerabilities occur. Findings appear inline in pull requests with the specific code path, exploitation context, and a suggested fix. Critical web application vulnerabilities block the merge; informational findings are tracked without friction.
Protect your web application with Rafter — setup takes under two minutes.