Microservices

Category: Web

Description

I just learnt about microservices. That means my internal server is safe now right?

I'm still making my website but you can have a free preview

Alternative links:

Attachments: dist.zip

Upon examining the codebase, we have identified three services: admin_page, homepage, and gateway.
To obtain the flag, we need the admin (logic in / endpoint of admin_page) to access the / endpoint of the homepage.
We can leverage the gateway to forward our request to the admin_page, which will redirect the admin to the homepage and ultimately render the flag.html.
To achieve this, we need to make a request to the gateway with the service parameter set to admin_page, indicating that we want to forward the request to the admin_page.
At the admin_page, we need to satisfy the conditions service != None and service != admin_page and requested_url != None.
For the first condition, the gateway already forwards service=admin_page since we want to forward our request to the admin_page. To meet the service != admin_page condition, we can employ parameter pollution by "overwriting" the previous value of service. This can be accomplished by defining service=1 (or any value) after the previous service. The logic for retrieving query parameters differs between the gateway and the admin_page, which is why fulfilling the first condition is possible.
To fulfill the second requirement, we can simply specify the url as http://home_page, prompting the admin to navigate to that URL, which will trigger the rendering of the flag template.

This is the final URL required to retrieve the flag:

Text Only
1	`http://34.124.157.94:5004/?service=admin_page&service=1&url=http://home_page`

Flag: grey{d0ubl3_ch3ck_y0ur_3ndp0ints_in_m1cr0s3rv1c3s}