Race Conditions#

What are Race Conditions ?#

Basically Race Conditions are Conditions where you webapp is out of the synchronization, so it if you would send a packet more then one time even 100s of times in a single second than you could exploit the website

Example#

Websites where you can buy something always have a place to redeem your coupon codes of some kind. If the website doesn’t apply rules to this feature we can exploit it and redeem a coupon code 100s of times in a single second and bypass the one time use feature so we can get something really cheap

CAUTION

This is off course highly illegal and I won’t take responsibility, this is for education only and for websites that you allowed to test if they have this issue

Okay lets start this TryHackMe called Race Conditions

IMPORTANT

You need to have premium to go through this box

The first 4 task should be self-explanatory so if you read them correctly you should answer them easy

Task 5#

This is where it gets hard, you need to use either the attackbox for this task or your own machine with Burp Suite on it

First you need to open Burp Suite and go to the proxy tab there you can open the browser but don’t turn on intercept yet

go to the website and login into one of the accounts

You can turn now intercept on and send some money over the other account

now you should see a POST request in the proxy tab

you can know Ctrl+R or right click and send it to repeater but don’t turn intercept off

you can now make a group

and duplicate 20 times

if you are finished with that you can select send group (parallel) this is important! and send it

now you can turn intercept off and see the magic

you need to repeat the sending part (with intercept on) till you get 100$ in one account and log in to that account to get the flag

The flag THM{PHONE-RACE}

we can now move on

Task 7#

This task is the same as Task 5, but now you have 3 accounts but its basically identical

I put here the step-by-step guide with picture but first try it yourself and if you get stuck go through the pictures and see what you did wrong then try again alone

IMPORTANT

Don’t forget to turn on intercept before you send the packets and only turn on intercept to get the POST packet first then turn it on again when you see the screen successful

The flag THM{BANK-RED-FLAG}