发现phpsessid

从上述提示
提示发送post请求，并且带有参数margin
发送后发现报文头部有一个字段叫flag，但好像每一次flag都不一样
构建Python脚本

request = requests.Session()data = {'margin':'find',
}
for i in range(50):html = request.post(url='http://114.67.175.224:17396/',data=data).headers['flag']print(html)

得到大量不同flag

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解码

这里给的每一个flag都不一样，楞了一下
想到了还有一个不知道值的margin参数
将这个值传入参数中
经过解码后发现一次解码为这样

再次对后面进行解码

这是二次解码后
将这个数字值当做margin发送post请求

得到flag
完整Python的exp程序

import requests
import re
import base64request = requests.Session()
right_data = ''
data = {'margin': '',
}for i in range(100):if i==1:data = {'margin': right_data,}html = request.post(url='http://114.67.175.224:17396/', data=data).textprint(html)breakhtml = request.post(url='http://114.67.175.224:17396/',data=data).headers['flag']#print(html)lift_data = str(base64.b64decode(html.encode('utf-8')),'utf-8')[:-8]right_data = str(base64.b64decode(html.encode('utf-8')),'utf-8')[-8:]right_data = str(base64.b64decode(right_data),'utf-8')data = lift_data+right_dataprint(data)