Efficient character-level taint tracking for Java

摘要

Over 80% of web services are vulnerable to attack, and much of the danger arises from command injection vulnerabilities. We present an efficient character-level taint tracking system for Java web applications and argue that it can be used to defend against command injection vulnerabilities. Our approach involves modification only to Java library classes and the implementation of the Java servlets framework, so it requires only a one-time modification to the server without any subsequent modifications to a web application's bytecode or access to the web application's source code. This makes it easy to deploy our technique and easy to secure legacy web software. Our preliminary experiments with the JForum web application suggest that character-level taint tracking adds 0-15% runtime overhead.