mhackeroni rulez
28 January 2019

Butterfree - Codegate Quals 2019

by chq-matteo

How not to pwn a modified 2018.11.18 Webkit

Download 2018.11.18 Webkit and Modified 

nc 17423 

We are given access to a JavaScriptCore shell.
There was an hint on the official discord of the ctf that there was an unintended solution to this challenge, specifically a one-liner.

Given the hint we tried to require some path where the flag could be at.

Executing require('flag') we get a syntax error related to ‘{‘.

We found that there is a debug feature in jsc shell that allows read from the file system

In the end the solution to the challenge is

> console.log(readFile('flag'))

The intended solution is very similar to

tags: codegate - ctf - unintended - mhackeroni