Understanding and Eliminating SQL Injection

Created by Kevin Feasel

Who Am I? What Am I Doing Here?

Catallaxy Services
Curated SQL
We Speak Linux

What Is An Injection Attack?

SQL injection is not the only injection attack available.

  • Javascript (e.g., cross-site scripting)
  • LDAP
  • NoSQL databases (e.g., MongoDB)

An injection attack is when you insert code in a manner the application developers did not expect.

Example: your text box populates @Parameter to do a lookup on a table. An attacker overloads @Parameter to perform some unexpected operation.

Another way of thinking about injection attacks: getting "outside" the parameter.

Why Should I Care?

Why Should I Care?

So you don't end up on this list...

What Can An Attacker Do?

  • Get schema information
  • Get protected data
  • Perform "administrative" tasks
    • Create bogus user accounts (including administrative accounts)
    • Create, drop, or alter tables or views
    • Delete, update, or insert data
  • Run arbitrary executable code

What SQL Injection Vulnerability Tells Me

Because of how easy it is to stop SQL injection, your application being susceptible indicates that you may have bigger problems, like:

  1. Using administrative accounts instead of least-privilege accounts
  2. Not protecting against other web application attacks (e.g., cross-site scripting, cross-site request forgery, or iframe injection)
  3. Not having measures in place to protect against data loss
  4. Not taking appropriate care of sensitive data (e.g., not hashing passwords properly, storing card data in violation of PCI standards)

Demo Time

Wrapping Up

There is one and only one way to protect yourself against SQL injection: parameterize your queries.

To learn how to do this for non-ASP.Net solutions, go to http://bobby-tables.com.


To learn more, go here: http://CSmore.info/on/sqli

And for help, contact me: feasel@catallaxyservices.com | @feaselkl