sandboxA security measure in the Java development environment. The sandbox is a set of rules that are used when creating an applet that prevents certain functions when the applet is sent as part of a Web page. When a browser requests a Web page with applets, the applets are sent automatically and can be executed as soon as the page arrives in the browser. If the applet is allowed unlimited access to memory and operating system resources, it can do harm in the hands of someone with malicious intent. The sandbox creates an environment in which there are strict limitations on what system resources the applet can request or access. Sandboxes are used when executable code comes from unknown or untrusted sources and allow the user to run untrusted code safely.
The Java sandbox relies on a three-tiered defense. If any one of these three elements fails, the security model is completely compromised and vulnerable to attack:
- byte code verifier -- This is one way that Java automatically checks untrusted outside code before it is allowed to run. When a Java source program is compiled, it compiles down to platform-independent Java byte code, which is verified before it can run. This helps to establish a base set of security guarantees.
- applet class loader -- All Java objects belong to classes, and the applet class loader determines when and how an applet can add classes to a running Java environment. The applet class loader ensures that important elements of the Java run-time environment are not replaced by code that an applet tries to install.
- security manager -- The security manager is consulted by code in the Java library whenever a dangerous operation is about to be carried out. The security manager has the option to veto the operation by generating a security exception.
Stay up to date on the latest developments in Internet terminology with a free weekly newsletter from Webopedia. Join to subscribe now.
Webopedia's student apps roundup will help you to better organize your class schedule and stay on top of assignments and homework. Read More »List of Free Shorten URL Services
A URL shortener is a way to make a long Web address shorter. Try this list of free services. Read More »Top 10 Tech Terms of 2015
The most popular Webopedia definitions of 2015. Read More »
Java is a high-level programming language. This guide describes the basics of Java, providing an overview of syntax, variables, data types and... Read More »Java Basics, Part 2
This second Study Guide describes the basics of Java, providing an overview of operators, modifiers and control Structures. Read More »The 7 Layers of the OSI Model
The Open System Interconnection (OSI) model defines a networking framework to implement protocols in seven layers. Use this handy guide to compare... Read More »