Gears of web exploits that sync in harmony; SteamCoin write-up from HTB University CTF 2021

In this write-up, we’ll go over the solution for the challenge SteamCoin that requires the exploitation of multiple server-side and client-side vulnerabilities. The solution involves a JWT authentication bypass through JKU claim misuse using unrestricted file upload, HTTP request smuggling for ACL bypass, and XSS to CSRF on an automated UI testing service to exfiltrate the flag from CouchDB.

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Tags :

[ HTB  uni-ctf  ctf  web  cve-2021-40346  scripting  request-smuggling  blind-xss  jwt  csrf  write-up  ]