Sqli-libs range 23-24 filtration and secondary injection practice

Less-23

       Get Type single quotation mark error injection

       Input filtered -- # And replace it with empty , So use single quotation marks to close

http://127.0.0.1/sql/Less-23/?id=1' and 1='1

       Search directly for known data , success

http://127.0.0.1/sql/Less-23/?id=1' and extractvalue(1,concat(0x7e,(select username from users limit 0,1),0x7e)) and 1='1

Less-24

       The secondary injection , View source code

       You can see that the login page imposes strict restrictions on user input , The registration page does not , By constructing the user name admin’# Content can be written to the database , And then directly modify the password ,’# take effect , The actual modified user name is admin, In this way, the modification is achieved admin Effect of password , You can use our newly modified password to log in .

       register admin’# account number

       Sign in admin’# account number

      

       modify admin Account and password

      

       Use admin Account to log in