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.
Taking ownership of our own misjudgments or simple forgetfulness takes a healthy amount of humility and some honest self-assessment. Yet sometimes... Read More »Have We Become a World of Addicts?
It's hard to imagine our lives without smartphones. But people who suffer separation anxiety when they don't have their phones nearby may be in... Read More »13 Best Free Android Apps
From secure messaging to document editing, our top free must-have apps have been rated, reviewed and named the best free Android apps of 2015. Read More »
From wacky alarm clocks to lecture hall tools and after class entertainment, these Android apps are a good fit for a student's life and budget. Read More »Network Fundamentals Study Guide
A network is a group of two or more computer systems or devices, linked together to share resources, exchange files and electronic communications.... Read More »Computer Architecture Study Guide
This Webopedia study guide describes the different parts of a computer system and their relations. Read More »
Stay up to date on the latest developments in Internet terminology with a free weekly newsletter from Webopedia. Join to subscribe now.
- Watch Datamation's editor James Maguire moderate roundtable discussions with tech experts from companies such as Accenture, Dell, Blue Jeans Network, Microsoft and more »