Google XSS Game - Solving Level 1

Level 1

Link: https://xss-game.appspot.com/level1

Solution

<script>alert('xss')</script>

Result

Analysis

This task needs only the basic knowledge. Lets see why the most primitive injections work here rightaway. Lets do a simple query and inspect the resulting HTML page.

Using the query with ' as a special character

Result of query. The special character ' apears in the result

The provided query text is placed directly in a <b> element

Conclution

1. Provided query text passed as a URL query parameter to the second page.
2. The special character (') in the query string was not filtered out. This indicates it might be possible to push special characters like <, >, ', ", / which can be used to inject a code.
3. Provided text apeared directly inside a <b> tag. Which indicate a script tag would be executed without any problem if it was set in between the <b> and </b>.