6
The term SQL
Injection can be
interpreted
into two
meanings:
an action of
hacking that
is done in the client application, modifying the SQL command that is in the client
application memory. The other meaning is a
web applications exploit technique which
uses the database for data storage.
The most common reason of SQL Injection is lack of the handling the characters - one
character
quotes' and
also
double
minus
character
“--“which
can
cause
an
application
hijack with SQL commands. The second one a hacker inserts SQL commands into a
parameter and a form address.
The SQL Injection bug would also be danger because first reason this technique allows a
person
can
log
into
the
system
without
having to
have
an
account,
second
reason in
addition SQL
injection also allows someone change, delete, or add
the data
that
resides
in a database, third reason even
more dangerous is
more off the database
itself, so that
it
cannot provide service to the web server.
Example syntax SQL in ASP
1)
$
SQL = "select *
from
login where
username = '$ username' and password = '$
password'", (from GET or POST variable)
2)
fill in the password with the string 'or''='
3)
then
the result will be
like
this SQL =
"select *
from
login where
username = '$
username' and
password
=
'pass' or'='";,
(with
the
selection
of this
SQL
will
always be TRUE)
 |