RE: Betr.: Exploiting C# Issues

Hello,

> -----Original Message-----
> From: Philip Wagenaar [mailto:p.wagenaar@accon.nl]
> Sent: Friday, February 04, 2005 9:44 AM
> To: pen-test@securityfocus.com
> As you know C#,VB.NET and Cobolt.NET etc etc all compile into the 
> Common Runtime Language.

True, however keep in mind that every compiler has it's own set of 
idiosyncrasy, read: optimization that result in a way it creates CLR code. For 
example VB compiler is inserting nop opcodes sometimes probably for easier 
breakpoint insertion during debugging. A good example of how compilers differ 
might be how internally Win32 C++ compilers pass "this": most are using ecx 
register but not all.   
 
> I am not aware of any big weaknesses in the CLR, but I would 
> search for papers on the CLR instead of a specific .Net Language.
Start with reading something about .NET security model. As for CRL code you can 
use IDA Pro or ILDASM (which is free and comes with SDK) to look for problems 
at compiled code level. You can also look at places where unmanaged code is 
being called as it might be possible that while there is no vulnerability in 
particular CLR application by itself you might be able to exploit security 
problem in called DLL.

Exploiting .NET is similar to exploiting weaknesses in Java VMs; I would start 
looking at already described class of problems for most popular JVM 
implementations and try to do the same to .NET Framework. 

Also keep in mind that .NET Framework Beta 2 is available to download.

Best Regards,
Aleksander Czarnowski
AVET INS