INSCTF20Q LowDeep

Challenge

Try out our new ping platform: http://lowdeep.insomnihack.ch. (Note: Only works with HTTP)

Solution

Interesting, it allows ips and hostnames. It behaves like ping itself. Maybe we need to try a Remote Code Execution attack here.

Let's see if it attempts to interpret other commands with: localhost;ls

Unfortunately, we can't just use cat.

So let's visit the page instead: http://lowdeep.insomnihack.ch/print-flag

And we get the following file:

$ file print-flag
print-flag: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/l, for GNU/Linux 3.2.0, BuildID[sha1]=72c589834f878a6a3267944f305c29166a1ace8b, stripped
$ chmod +x print-flag
$ ./print-flag
INS{Wh1le_ld_k1nd_0f_forg0t_ab0ut_th3_x_fl4g}

Flag

INS{Wh1le_ld_k1nd_0f_forg0t_ab0ut_th3_x_fl4g}