Creating an AppDomain with limited permissions

Easily Creating a StrongNameMembershipCondition for an Assembly

.Net Security Blog — Tue, 26 Oct 2004 23:58:00 GMT

Easily Creating a StrongNameMembershipCondition for an Assembly

.Net Security Blog — Tue, 26 Oct 2004 23:58:00 GMT

re: Creating an AppDomain with limited permissions

Kevin Westhead — Tue, 02 Nov 2004 12:31:00 GMT

Could you elaborate on why you would assign evidence to the AppDomain? In other words, how does it make the AppDomain more secure and what potential security holes does it plug that permission sets alone cannot?

An Enhanced Version of the Sandboxed AppDomain

.Net Security Blog — Tue, 02 Nov 2004 21:53:00 GMT

re: Creating an AppDomain with limited permissions

Shawn — Tue, 02 Nov 2004 19:08:00 GMT

Hi Kevin,

Good question ... I think I may turn this into a seperate post. The easiest example of an instance where an AppDomain needs evidence assigned to it is the case where a web page is hosting some managed code. In this case, the page might point at some code that lives on the local machine in the GAC, and therefore recieves a high level of trust.

Now imagine that an exploit is found in this code, and by calling into a specific entry point, I can elevate my permissions and do whatever I want. Now, if my web page doesn't load any code of its own, the only code on the callstack will be the buggy component in the application. This means that if you don't take into account the AppDomain, an arbitrary web page can now exploit code sitting on my machine.

Thankfully we do take the AppDomain into account, and all code hosted on a web page gets run in an AppDomain with a set of evidence that severly limits its permission grant. For more information about that (from the other perspective) check out: http://blogs.msdn.com/shawnfa/archive/2003/06/26/57026.aspx

-Shawn

Peter Torr Provides More Details on Sandboxing AppDomains

.Net Security Blog — Mon, 08 Nov 2004 20:30:00 GMT

New and Notable 66

Sam Gentile's Blog — Sat, 20 Nov 2004 20:12:00 GMT

New and Notable 66

Sam Gentile's Blog — Sat, 20 Nov 2004 20:13:00 GMT

Don't Deny SkipVerification

.Net Security Blog — Fri, 11 Mar 2005 04:41:00 GMT

The Simple Sandboxing API

.Net Security Blog — Mon, 08 Aug 2005 20:04:35 GMT

A while back I gave some sample code to show how to setup a sandboxed AppDomain.&nbsp; This technique...