This was a nice little web challenge from sCTF. I’m trying to do more web challenges as it’s one of my weaker areas.

Challenge:

The ducks and I have a unfinished score to settle.
http://ducks.sctf.michaelz.xyz/

Hint:
If you’ve remember HSF, you’ll know that The Ducks is unsolvable.

Challenge:

Welcome to Vertinet.

This problem follows the same specifications as the previous Verticode problem, except that you have to solve many of them by developing a client to communicate with the server available at problems1.2016q1.sctf.io:50000. Good luck.

This was a nice little challenge from sCTF 2016. I’m trying to work on more tricky stuff, but this one looked like fun and I couldn’t resist.

Challenge:

Welcome to Verticode, the new method of translating text into vertical codes.

I only managed one task in the 2016 VolgaCTF, but it was a fun one. Coding a tic tac toe bot.

Challenge:

Tic-Tac-Toe

An important step towards the strong AI is the ability of an artificial agent to solve a well-defined problem. 
A project by the name 'tic-tac-toe' was one of such test problems. It's still up...

nc tic-tac-toe.2016.volgactf.ru 45679

Challenge:

EquationSolver (exp60)

Description:

I created a program for an unsolveable equation system. My friend somehow forced it to solve the equations. Can you tell me how he did it?

Challenge:

File Checker (rev60)

Description:

My friend sent me this file. He told that if I manage to reverse it, I’ll have access to all his devices. My misfortune that I don’t know anything about reversing :/

Challenge:

FlagStore (exp70)

Description:

Here’s the ultimate flag store. Store and retrieve your flags whenever you want.

Challenge:

It’s Prime Time! (code60)

Description: We all know that prime numbers are quite important in cryptography. Can you help me to find some?

Service: 188.166.133.53:11059

Solution:

Running netcat against the address gave the following output:

> nc 188.166.133.53 11059
Hi, you know that prime numbers are important, don't you? 
Help me calculating the next prime!
Level 1.: Find the next prime number after 5:

I haven’t done much work with Ruby, but this little challenge from the Internetwache CTF looked interesting.

Challenge:

Ruby’s count (exp50)

Description: Hi, my name is Ruby. I like converting characters into ascii values and then calculating the sum.

Service: 188.166.133.53:12037

Solution

The first thing to do was to poke the service using netcat:

> nc 188.166.133.53 12037
Let me count the ascii values of 10 characters:
> 123
WRONG!!!! Only 10 characters matching /^[a-f]{10}$/ !