Path Traversal

Improper File Access • Intermediate

File Systems

Secure Mode• show fix Session• Cookie Recruiter• Mode

Objective: Access files outside the intended directory.

Try: Manipulate the file path.

📁 Design: Directories are boundaries. Traversal is crossing the boundary.

Everything here is simulated and sandboxed to this site—no real accounts, no real services.

Demo How it works Issue Exploit Fix Video

1) Demo

Here is the feature “working” as implemented in this mode.

App Output

Filesystem

/public └─ readme.txt /private └─ secrets.txt

Requested Path

public/readme.txt

File Contents

This is a public file accessible to all users.

Response

Status: 200 OK Response Headers: (none)

2) How the code works

This section shows the mental model: what the server is “thinking”.

return readFile(request.query.file);

3) The issue

User-controlled paths can escape intended directories.

Real-world impact: Leaking config files, keys, internal source code.

4) Exploit it

Edit the raw request below. You can change method, path/query, headers, and body. Then send it. The server will parse what you typed and re-run the simulation.

Request Editor

Tip: For secure mode tests, add a cookie like: Cookie: session=1; role=Admin

Parsed View (what the server read)

method: GET path: /download?file=public/readme.txt headers: host: kylerburke.dev body: (empty)

Exploit Editor Hidden (Recruiter Mode)

This mode is designed for sharing your portfolio. It focuses on clear explanation, real-world impact, and fixes—without interactive exploitation.

Want to demo the exploit? Turn Recruiter Mode off and use the Request Editor.

5) Fix

Secure Mode shows the fix behavior. Flip modes and send the same request.

Normalize paths and enforce allowlisted directories.

Video

Short visual explanation to match what you just did.

Swap the YouTube ID in the Worker to pick a different explainer video for this vulnerability.