It hurts my head to see people refer to a "sandbox" as if the term means anything in isolation. Sandboxing is a strategy that covers a broad spectrum of impleme

It hurts my head to see people refer to a "sandbox" as if the term means anything in isolation. Sandboxing is a strategy that covers a broad spectrum of implementation quality. Take Java's "sandbox," which is just its VM layer employing a complicated stack inspection based permission model. In practice it's very porous, and has a very poor security history at various levels. You also mentioned Flash, which has a VM "sandbox" for Actionscript, with a simpler, mostly origin-based security model. Depending on the platform there's also an outer Flash sandbox using OS-based security primitives to various degrees. Since Adobe built their own NPAPI sandbox on Windows (mostly for Firefox), it's a good one to point to. It prevents write-level access to most objects, and relies on a broker process to manage those actions. Most objects are readable from inside the sandbox, and various low-privilege objects can be directly controlled as well. Historically, Flash has a better security track record than Java, but has still had its share of issues. Then there's the Chrome sandbox. Once again, there's a VM level "sandbox" for JavaScript and one for NaCl nexes, both using a strict origin-based security model. Then there's an outer sandbox using the OS-based primitives that deny access to all objects, requiring all resource access to be routed through a broker process. Chrome is generally considered to be very good on the security front, and has yet to be hit with an exploit in the wild. I could actually into very deep detail on how these differ, and the effectiveness of each sandbox implementation, but I think the broad descriptions convey my point.