The widespread adoption of web services as an instant means of information dissemination and various other transactions, has essentially made them a key component of today?s Internet infrastructure. Web-based systems comprise both of infrastructure components and of applicationspecific code. Various organizations have started extensively deploying Intrusion Detection/Prevention Systems and Firewalls as a means of securing their vital installations. However, very little emphasis is laid on securing the applications that run on these systems, apart from frequent updates and patching. SQL-Injection Attacks are a class of attacks that many of these systems are highly vulnerable to, and there is no known fool-proof defense against such attacks. In this paper, we propose a technique, which combines static application code analysis with runtime validation to detect the occurrence of such attacks. The deployment of this technique eliminates the need to modify source code of application scripts, additionally allowing seamless integration with currently-deployed systems. We provide various optimizations improving overall efficiency, and also preliminary evaluation of prototype developed.