Room 3

09:00 - 10:00 (UTC+02)

Talk (60 min)

Sandboxing .NET assemblies for fun, profit and of course security!

In our current way of developing .NET applications we rely a lot on third-party libraries developed by others. This of course has a lot of benefits from productivity perspective because there is no need to write needed functionality from scratch.

But by using in a third-party library you also pull in it's issues and possibly security problems that are found over time. What does the library do? And what type of other libraries and/or functionality does it rely on? What do the projects/people behind it do for security?
If we develop a .NET application using external libraries can we improve our security posture? Other new technologies like WebAssembly introduced a concept of nano-process, which allows the developer to limit the capabilities available for an external module by creating a restricted sandbox for it. Could we maybe do the same in .NET? In the old days we could use AppDomains and Code-Access Security (CAS) to achieve that, but with the introduction .NET Core there only is a single AppDomain and CAS has been deprecated.
Luckily with .NET Core we did get more internals exposed on AssemblyLoadContext and in this session we're going to create a sandbox using that. A restricted sandbox that limits the functionality available that will improve the security posture of our application!

Niels Tanis

Niels Tanis has got a background in .NET development, pentesting and security consultancy. He also holds the CSSLP certification and has been involved in breaking, defending and building secure applications. He joined Veracode in 2015 and right now he works as a security researcher on a variant of languages and technologies related to Veracode’s Binary Static Analysis service. He is married, father of two and lives in a small village just outside Amersfoort, The Netherlands.