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picoCTF 2022 | RPS Write-up
Here’s a program that plays rock, paper, scissors against you. I hear something good happens if you win 5 times in a row. Connect to the program with netcat: $ nc saturn.picoctf.net 53865 The program’s source code with the flag redacted can be downloaded here. Category: Binary Exploitation Since this is a binary exploitation challenge…
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picoCTF 2022 | Roboto Sans Write-up
The flag is somewhere on this web application not necessarily on the website. Find it. Check this out. Category: Web Exploitation While the challenge’s title is indeed the name of a popular font, this is a clever pun, hinting towards the main target of the challenge: the robots.txt file. robots.txt is a file used to…
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picoCTF 2022 | Power Cookie Write-up
Can you get the flag? Go to this website and see what you can discover. Category: Web Exploitation This is the first cookie-based challenge of the 2022 batch, and a simple one to start off with. Let’s get started by going to the website in the challenge description, and pressing “Continue as guest”. At this…
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picoCTF 2022 | Fresh Java Write-up
Can you get the flag? Reverse engineer this Java program. Category: Reverse Engineering As the challenge suggested, I threw the provided program at an online Java decomplier. I used this one. You can make out the flag by looking at each character the program checks for, from the bottom up. The re-assembled flag reads: picoCTF{700l1ng_r3qu1r3d_84e23997}
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picoCTF 2022 | Forbidden Paths Write-up
Can you get the flag? Here’s the website. We know that the website files live in /usr/share/nginx/html/ and the flag is at /flag.txt but the website is filtering absolute file paths. Can you get past the filter to read the flag? Category: Web Exploitation First, I tried to input /flag.txt, but that sadly doesn’t work.…
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picoCTF 2022 | bloat.py Write-up
Can you get the flag? Run this Python program in the same directory as this encrypted flag. Category: Reverse Engineering Our first step after downloading the files will be to look through the python program. The code here is purposefully written to be confusing for the reader, with the aim of obfuscating the program’s true…
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picoCTF 2022 | unpackme.py Write-up
Can you get the flag? Reverse engineer this Python program. Category: Reverse Engineering Since this is a reverse engineering problem, let’s start by looking at the code for this python program. We can see a payload (seemingly encoded in base64), which will be decrypted using the key_str variable, itself encoded in base64.After this, the decoded…
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picoCTF 2022 | transposition-trial Write-up
Our data got corrupted on the way here. Luckily, nothing got replaced, but every block of 3 got scrambled around! The first word seems to be three letters long, maybe you can use that to recover the rest of the message. Download the corrupted message here. Category: Cryptography Looking at the provided file gives us…
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picoCTF 2022 | substitution0, substitution1, and substitution2 Write-up
substitution0: A message has come in but it seems to be all scrambled. Luckily it seems to have the key at the beginning. Can you crack this substitution cipher? Download the message here. substitution1: A second message has come in the mail, and it seems almost identical to the first one. Maybe the same thing…
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picoCTF 2022 | Sleuthkit Intro Write-up
Download the disk image and use mmls on it to find the size of the Linux partition. Connect to the remote checker service to check your answer and get the flag. Note: if you are using the webshell, download and extract the disk image into /tmp not your home directory. Download disk image Access checker…
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