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A daily CTF challenge with a fun new puzzle every day

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Today's Challenge
tchentchen
Nano Services
Web
Medium
16 solves
Submissions (latest 3)
rsk0315

SOLVED!

Jun 28, 5:20 PM

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admin
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Rows:

Nano Services

Topic: XSSReleased: Jun 29, 2026

16 solves
Web
Medium

by

tchen

tchen

Very small services.

Beginner Hint 1: About the Admin Bot
  • In this challenge, you are given not only the web application itself but also an Admin Bot.
  • The Admin Bot has a cookie containing the flag, and it opens a specified path using headless Chrome.
  • Therefore, your goal is to make the Admin Bot trigger your payload and send the cookie value to an external server.
  • You can prepare your own server as the destination or use an existing service that lets you receive and inspect HTTP requests.
  • If you are not yet familiar with how to use the Admin Bot or how to inspect incoming requests, it may help to solve Fushigi Crawler first and read its writeup.
Beginner Hint 2: Approach
  • The cookie has the HttpOnly flag enabled. This means that even if you succeed in XSS, you cannot leak the cookie using document.cookie.
  • It looks like there are 3 functions you can choose from via the func parameter. Is that all?
nano-services.tar.gz

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