HSCTF 2019

Just one byte makes all the difference.

Author: HSN CS Club

Training wheels!

Author: HSN CS Club

I've been really into Super Smash Brothers Melee lately... Note: If you're trying to use python or a similar program to run your exploit, make sure to keep stdin alive with cat.

Author: HSN CS Club

Julius Caesar's back, and he's not happy...

Author: HSN CS Club

Rob wants to write a song, but he doesn't know what to say. Help him write his way to a shell.

Author: HSN CS Club

Keith made a cool license-checking program but he forgot the flag he used to create the key! To make matters worse, he lost the source code and stripped the binary for his license-generator program. Can you help Keith recover his flag? All he knows is:

The license key is 4-EZF2M-7O5F4-V9P7O-EVFDP-E4VDO-O He put his name (in the form of 'k3ith') as the first part of the flag There are 3 underscores The flag is in the format hsctf{} The flag doesn't have random character sequences (you should be able to read the entire flag easily). The flag only contains lowercase English letters and numbers. The generator might produce the same keys for different inputs because Keith was too lazy to write the algorithm properly.

Author: HSN CS Club

Unicode? ...da heck?

Use flagCheck to input the flag you get from the challenge to get the actual flag

Author: HSN CS Club

There's nothing like executing my own code in Java in my own special way.

Author: HSN CS Club

Pirate Keith loves cryptography and has protected his treasure with a very annoying caesar shift. He has witten “CGULKVIPFRGDOOCSJTRRVMORCQDZG” on his treasure chest and has left a piece of paper with the following message: “every subsequent letter is shifted one less than the previous.” Knowing this, can you unlock Pirate Keith’s treasure chest?

This challenge does not have any files to run, solve the challenge from above info and put the flag in the flagCheck binary to get the actual flag

Author: HSN CS Club

Crypto land is fun! Decrypt:

KZ6UaztNnau6z39oMHUu8UTvdmq1bhob3CcEFdWXRfxJqdUAiNep4pkvkAZUSn9CvEvPNT5r2zt6JPg9bVBPYuTW4xr8v2PuPxVuCT6MLJWDJp84

Use flagCheck to input the flag you get from the challenge to get the actual flag

Author: HSN CS Club

You think you are worthy of obtaining the flag? Try your hand at The Quest to Obtain the Flag.

https://forms.gle/7pyAWuG3GvYL443NA

Hint: Maybe you don't have to complete the challenges...

Use flagCheck to input the flag you get from the challenge to get the actual flag

Author: HSN CS Club

Keith is up to some evil stuff! Can you figure out what he's doing and find the flag?

Note: nothing is actually saved

Use flagCheck to input the flag you get from the challenge to get the actual flag

Use sudo unzip filename to unzip the file if needed.

Author: HSN CS Club

Don't get slapped too hard.

Use flagCheck to input the flag you get from the challenge to get the actual flag

Author: HSN CS Club

I got a weird image from some fish. What is this?

Use flagCheck to input the flag you get from the challenge to get the actual flag

Author: HSN CS Club

My friend sent me this file, but I don't understand what I can do with these 6 different characters

Use flagCheck to input the flag you get from the challenge to get the actual flag

Author: HSN CS Club

My friend gave me some fancy text, but it was reversed, and so I tried to reverse it but I think I messed it up further. Can you find out what the text says?

Use flagCheck to input the flag you get from the challenge to get the actual flag

Author: HSN CS Club

This image seems wrong.....did Keith lose the key again?

Use flagCheck to input the flag you get from the challenge to get the actual flag

Author: HSN CS Club

My friend says that there is a bug in my REPL. Can you help me find it?

Hint- What happens to the given input?

Author: HSN CS Club