perform SQL injection and patch it

Question

$sql="SELECT * FROM  Reg_Stud WHERE Username='$var1' AND RegID=$var2 ";

this is the code...

i tried the input

Username =anything' OR 'x'='x

ID =12 or 1=1

no sign of sql injection...but when i just give the 1st argument and end it by commenting the rest...it gives sql error i.e anything' OR 'x'='x;--

Answer 1

perform SQL injection and patch it

You can use SQL Inject Me Firefox addon which has huge number of patterns it tests with :)

SQL Injection vulnerabilites can cause a lot of damage to a web application. A malicious user can possibly view records, delete records, drop tables or gain access to your server. SQL Inject-Me is Firefox Extension used to test for SQL Injection vulnerabilities

To be on the safe side, you should use Prepared statements.

Answer 2

You have following conditions: Username==anything OR x=x AND RegID=12, in boolean: false OR true AND false. Apparently MySQL evaluates this entire expression as false ((false OR true) AND false).

Answer 3

What happens if you set the username to x' or 1=1--