ctf

We’re back again with another NodeJS web challenge from Gynvael. Let’s get into it! Description Just like the previous challenges, we are given the source code for the NodeJS application: const http = require('http') const express = require('express') const fs = require('fs') const path = require('path') const PORT = 5006 const FLAG = process.env.FLAG || "???" const SOURCE = fs.readFileSync(path.basename(__filename)) const app = express() const checkSecret = (secret) => { return [ secret. [Read More]

Category: Space and Things Description: Help the Launchdotcom team perform a mission on their satellite to take a picture of a specific location on the ground. No hacking here, just good old fashion mission planning! Connect to the challenge on mission.satellitesabove.me:5023. Using netcat, you might run nc mission.satellitesabove.me 5023 Write-up by medarkus, nafod This write-up is part of a larger post hosted over at our official blog. On connection to the service, we’re presented with the following instructions: [Read More]

It was recently brougt to my attention that Gynvael Coldwin has been releasing some CTF-style Express.js web challenges, so I decided to give them a try :) As of 5/12/2020, there are only 3 challenges published Level 1 Level 1 begins here, where we are presented with a standard layout for this type of web challenge: a blank page with the JS source echoed back to us. Source code Level 1 const express = require('express') const fs = require('fs') const PORT = 5001 const FLAG = process. [Read More]

This is one of the reversing problems that I solved during SarCTF a couple months back in February of 2020. I decided to write this up since I believe it to a good beginner problem for people looking to get into reverse engineering. Problem Description While the children were playing toys, Sherlock was solving crosswords in large volumes. Reversing the Binary Using file we can see we’re given an unstripped 64-bit ELF file: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/l, for GNU/Linux 3. [Read More]