Before we move on to ask fuel injection How can this deck be manipulated.
The first and easiest attack scenario can rely on inserting a payload directly in the argument of a
called function assume that an FPP server that we mentioned is vulnerable to buffer overflow.
We checked this by submitting increasingly longer strings as log in and password at some stage the server
failed.
This is visible because we analyze it via a debugger.
This means that an insertion point is found an insertion point is a place where bounds checking checking
an input value for length is not being applied.
How can the address of a return function be located now.
Find an opcode table for the targeted software.
It will contain memory addresses for system registers for the program.
The next step is preparing a payload.
It should be short and compact enough to be able to be transferred as a function call parameter.
The final point is padding the payload with an up slide.
This will increase the likelihood of the victim's computer executing your code in the program you aim
to control.
It's up to you entirely to choose what your code will do.
What is the danger related to this attack.
Attack services above all have a higher level of permissions than the permissions of a user who runs
an attack.
It's no use applying complex techniques to control the execution of a program you run since the program
will have your level of permissions system services usually run with escalated permissions that a user
doesn't have.
They for example run on remote machines.
This is often locally reasonable because programs perform some operations with escalated permissions.
If we were to seize control over this service this would make us in fact the administrator of the computer.
Let's now look into Eskew queery manipulation as well.
Unlike C and C++ languages is interpretive.
There's no compiled code and no compilers the languages use interpreters instead interpreters are programs
that translate strings if and analyze dring is well-formed.
Which means it conforms to the version of the Escuela standard that a given database server supports.
The server will execute it.
The source of the code is irrelevant.
Many applications allow user input examples of this practice or logging firms that require a user to
submit log in and password to log in.
You can't ensure that a potential attacker will not submit any other value to the form.
The form will accept any strings as skewl statements in particular can be entered as well.
The simplest case can include entering an expression that's always true for example or one equals one
a more sophisticated option could be 0 or 1 less than 2.
If an application is susceptible to this thread it will forward the submitted string to a database server
where it will be executed.
The string will be executed with the same permissions as the permissions of the application that connects
to the server.
If the application connects to a database server as the server's administrator which is a widespread
practice and makes as CULE injection a significant threat.
This means the code will certainly be executed provided it's well formed.
An administrator is able to run any instructions on his server.
The second factor that aggravates as Kule injection threat is the fact that developers are programmers
often join as Cuil statements fragments with user input.
They join strings for a database server.
The difference between the part of the string that is embedded in the application code and the part
that is supplied as a parameter.
For example a user name is indistinguishable.
The server executes all statements contrary to popular belief.
The location of the string Konk intonation whether it's on the side of the client application or on
the side of the database server via stored procedures does not alter the threat level at all.
We'll see this in a moment.
The first part of this presentation will cover some basic techniques for manipulating as Cuil queries
will check if we can really manage to log into a poorly written application and then examine the possibilities
of more sophisticated as CULE injection techniques.
Let's imagine typical circumstances for an attack
an application is poorly designed at first glance.
Usernames and corresponding passwords are stored in tables in a database there in plain text regardless
of what's contained in the database.
Anyone can access it.
The usage of inbuilt authentication mechanisms for a used environment ASAP dot net or ph P would be
preferrable.
In any case what we have here is a simple table containing a user name a user's password and information
on the user status whether or not he or she is a system or an application administrator.
Well entered two users into this table
in the system version we work with will have to do this row by row.
First we insert the date of the first user and then the data of the other user in a moment.
A log in form will be visible.
The form leads to an application that is prepared in this way the alter database
a client application checks at the Values submitted to the log in and password fields match the ones
in the rows in the table.
How is this done.
The simplest and the most dangerous solution is to execute the query given.
This will read all the table rows that contain user names and passwords that match the values we submitted.
Why is this method so dangerous.
It's because you can enter an always true expression instead of a valid log in or password string
one characteristic feature of an alt..
The Omaar operator is that if one operand is true the others value is practically irrelevant.
The result will always be true since the next part is a code fragment that checks passwords.
We don't want to execute.
What should we do then.
We need to mark the latter part of the string.
The commands at the right side as Commons to include inline comments and Eskew will use double dashes.
Let's check this solution without submitting a user name or password.
We're able to read all contents of the table.