# SharkyCTF – Give Away 1
* **Category:** PWN* **Points:** 275
## Challenge
> Make good use of this gracious give away.> > nc sharkyctf.xyz 20334> > Attachments :> > binary : give_away_1> >> > shared library : libc-2.27.so> > Creator: Hackhim## Solution
Well first of all we mark the binary as executable with 'chmod +x give_away_1'
then we run the binary and it gives us a cool give away (not yet ^_^)and receives som input after it :
![screenshot1](https://github.com/0d12245589/CTF-writeups/raw/master/2020/SharkyCTF/PWN/Give_away_1/images/screenshot1.png)
so what can we do with this giveaway ?
lets first find out what is it by dissassembling the binary using binary ninja :
![screenshot2](https://github.com/0d12245589/CTF-writeups/raw/master/2020/SharkyCTF/PWN/Give_away_1/images/screenshot2.png)
We see that the `system@GOT` address is leaked to us so we can easily determine the libc base address and initiate a ret2libc attack
I used pwntools to do this using python : [solve.py](https://github.com/0d12245589/CTF-writeups/raw/master/2020/SharkyCTF/PWN/Give_away_1/solve.py)
we run it and get the flag:
![screenshot2](https://github.com/0d12245589/CTF-writeups/raw/master/2020/SharkyCTF/PWN/Give_away_1/images/screenshot3.png)
```shkCTF{I_h0PE_U_Fl4g3d_tHat_1n_L3ss_Th4n_4_m1nuT3s}```
Yeah I hope you did :)