SansAlpha

https://play.picoctf.org/practice/challenge/436?originalEvent=73&page=4

Description

The Multiverse is within your grasp! Unfortunately, the server that contains the secrets of the multiverse is in a universe where keyboards only have numbers and (most) symbols.

Additional details will be available after launching your challenge instance.

So first, I tried some simple commands like ls, cd etc. and as expected, it did not work..

So I went to google to search around and found out about wildcards

Wildcardstldp.org

Since my teammates were also working with me on this, they also sent me some of their work which helped me while understanding this challenge and testing out some of the following commands:

After that i realised that if i put "64" with the command, it would output in Base64

flag is located at */????.???

However, this Base 64 is useless as it does not give me anything useful...

So I studied a bit more on this, and realised that the wildcard actually outputs 3 different binaries instead of 1 so we could actually store the command inside of a list and then run the command on the first binary.

So if i do something like _1=(/???/????64)

And then run the command "${_1[0]}" */????.???

cmV0dXJuIDAgcGljb0NURns3aDE1X211MTcxdjNyNTNfMTVfbTRkbjM1NV9iMGQ1ZTg1NX0=

After decoding it, we get return 0 picoCTF{7h15_mu171v3r53_15_m4dn355_b0d5e855}

picoCTF{7h15_mu171v3r53_15_m4dn355_b0d5e855}