Defense in Depth in Context

In the days of yore, a military technique called Defense-in-Depth was used to protect kingdoms, castles, and other locations where you might be vulnerable to attack. It's a layered defense strategy where the attacker would have to breach several layers of protection to finally reach the intended target. It allows the defender to spread their resources and not put all of the protection in one location. It's also a multifaceted approach to protection in that there are other mechanisms in place to help; and it's redundant so if a component failed or is compromised, there are others that are ready to step in to keep the protection in tack.

Information technology also recognizes this technique as one of the 'best practices' when protecting systems. The infrastructure and systems they support are fortified with a layered security approach. There are firewalls at the edge and often, security mechanisms at every segment of the network. Circumvent one, the next layer should net them. There is one little flaw with the Defense-in-Depth strategy - it is designed to slow down attacks, not necessarily stop them. It gives you time to mobilize a counter-offensive and it's an expensive and complex proposition if you are an attacker. It's more of a deterrent than anything and ultimately, the attacker could decide that the benefits of continuing the attack outweigh the additional costs.

In the digital world, it is also interpreted as redundancy. Place multiple iterations of a defensive mechanism within the path of the attacker. The problem is that the only way to increase the cost and complexity for the attacker is to raise the cost and complexity of your own defenses. Complexity is the kryptonite of good security and what you really need is security based on context. Context takes into account the environment or conditions surrounding an event to make an informed decision about how to apply security. This is especially true when protecting a database. Database firewalls are critical components to protecting your valuable data and can stop a SQL Injection attack, for instance, in an instant. What they lack is the ability to decipher contextual data like userid, session, cookie, browser type, IP address, location and other meta-data of who or what actually performed the attack. While it can see that a particular SQL query is invalid, it cannot decipher who made the request. Web Application Firewalls on the other hand can gather user side information since many of its policy decisions are based on the user's context. A WAF monitors every request and response from the browser to the web application and consults a policy to determine if the action and data are allowed. It uses such information as user, session, cookie and other contextual data to decide if it is a valid request. Independent technologies that protect against web attacks or database attacks are available, but they have not been linked to provide unified notification and reporting.

Now imagine if your database was protected by a layered, defense-in-depth architecture along with the contextual information to make informed, intelligent decisions about database security incidents. The integration of BIG-IP ASM with Oracle's Database Firewall offers the database protection that Oracle is known for and the contextual intelligence that is baked into every F5 solution. Unified reporting for both the application firewall and database firewall provides more convenient and comprehensive security monitoring. Integration between the two security solutions offers a holistic approach to protecting web and database tiers from SQL injection type of attacks. The integration gives you the layered protection many security professionals recognize as a best practice, plus the contextual information needed to make intelligent decisions about what action to take. This solution provides improved SQL injection protection to F5 customers and correlated reporting for richer forensic information on SQL injection attacks to Oracle database customers. It’s an end-to-end web application and database security solution to protect data, customers, and their businesses.

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Published Mar 16, 2011

Version 1.0