WAFs And SQL Injection

WAFs protect databases from SQL injection for only so long
The ModSecurity site is putting on the SQL Injection Challenge. Contestants are attempting to find successful SQL injection attacks against target applications. The four sample applications are from IBM, Cenzic, HP, and Acunetix, each with a slightly different host configuration and database platform.

There are two contests within the challenge. The first test is a timed event to see who can detect the database, table, and column names behind test applications. The second test is to find a vulnerability and avoid both inbound attacks and data extrusion detection. These applications have been previously scanned for common vulnerabilities and injection attacks, and there are active Web application firewalls running.

Remember that SQL injection is an attack on a database that goes through a firewall, an application, and, in some cases, a supporting Web application firewall as well. What's also important to note here is that these "test" applications are set up to be pretty secure.

The first phase of the event has been completed, and each of the platforms were successfully compromised. On average, it took 72 hours for an attacker to break in across the various contests and against each of the four applications. The test results demonstrate that a Web application firewall (WAF) will be breached by a persistent attacker. It's not a matter of if -- it's a matter of when. The real value of WAF technology is to monitor and detect attacks so you respond to the attack. That might mean updating your WAF rules, filtering some inbound connections, double-checking that input values are properly filtered, or even taking some of your services off line.

There are a few lessons to learn here, but paramount is that you need to be monitoring activity -- and actually reviewing the logs -- if you hope to catch and react to an attack. Static defenses only last so long.

Adrian Lane is an analyst/CTO with Securosis LLC, an independent security consulting practice. Special to Dark Reading.

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