S.H.E.L.L CTF 2021: Under Development

Under Development

Category: Web Security

50 points

http://3.142.122.1:8885/

Solution

Under given url there’s only This web app is still under development. message.

I’ve checked the source.

Ok, so let’s check the cookies.

Value of the cookie after urldecoding seems to be base64 dXNlcg==, which after decoding is user string. Let’s change it to admin (base64 encoded YWRtaW4=).

Flag

SHELL{0NLY_0R30_8e1a91a632ecaf2dd6026c943eb3ed1e}