HexBrain

HackerOne · Report #410451

User login page doesn't implement any form of rate limiting

Validstatus
lowseverity
42upvotes
4 Jan 2019disclosed

How it was found

Hi Team,

Summary: As a best practice a login page should have a rate limitting just like hackerone.com

Vulnerable Request

POST /auth/post_login HTTP/1.1
Host: ctf.hacker101.com
User-Agent: <redacted>
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Referer: https://ctf.hacker101.com/
Content-Type: application/x-www-form-urlencoded
Content-Length: 73
Cookie:<some cookie>
DNT: 1
Connection: close
Upgrade-Insecure-Requests: 1

csrf=<csrf token>&username=<target username>&password=<vulnerable parameter>

Steps To Reproduce

  1. Tamper login page and send the request to Burp Intruder
  2. Configure the payloads
  3. Start the Burp Intruder

Proof Of Concept ██████

Notice the Content Length as highlited on my screenshot

Impact

An attacker can freely bruteforce any username and can takeover any account

This report was disclosed publicly on HackerOne and belongs to its author and the program. See the original