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Vista: better security [Y/N] ?

Published: 2006-12-26
Last Updated: 2006-12-26 00:31:06 UTC
by Swa Frantzen (Version: 1)
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I went to a talk about Microsoft's Vista a little while ago and from what I remember of the presentation, some highlights of the security impact of Vista:
  • Vista has what's called "defense in depth" by Microsoft. Most of us think of something with multiple devices creating layers, but Microsoft uses the term for a way they use inside a machine to give processes and resources a level of trust. Low level processes cannot access higher classified assets.
    • IE has been given a low trust level. After asking questions it was still unclear if outlook would be low as well. It seemed the answer pointed to the attachments being low but outlook and the emails themselves not. But I might have misunderstood.
    • User processes are at a medium trust level.
    • Service processes are at a high level.
    • System is still the highest trust level.
  • Even when logged on with local admin rights, processes are not started by default with those rights. The demo was rather convincing with notepad refusing to save a file in c:\windows\ even though the user had admin rights. To start the application the local admin needs to right click and start notepad with additional rights.
  • There is a "secure desktop" used for switching users, logging in and being prompted for allowing additional rights needed by processes. The normal desktop is grayed out during such prompts making them rather hard to ignore. Note: the default is not accept but cancel. This secure desktop should somehow (unspecified how) make it more secure to do these prompts.
  • Signed application can voluntary say in their profile what they are expected to do and not to do. Vista will enforce that profile and terminate processes stepping outside of their profile. Eg.:
    An MTA could have a profile that it's only going to listen to port tcp/25.  Suppose the process gets exploited and starts to listen on another port to open up a backdoor: Vista could terminate the process right there.
    Since the thing is voluntary I'm wondering where the incentive will be for developers to use the belt and suspenders approach.
  • Virtualization: Once you tried once to get your users to give up local admin rights, you know it's a pain. For the least bit they need help and additional permissions. And just about any application you need won't play nice without a 10 round fight. Vista addresses this by virtualizing the filesystem for older "legacy" applications. If the application wants to drop an .ini file in c:\windows\, it's not given an error, but the file is dropped in an user owned directory instead. Reading obviously matches this to cheat the misbehaving application into working without having write access to critical directories.
  • The well publicized locking of kernel mode additions on 64bit kernels only (32bit would break drivers apparently, there are no to very few 64bit drivers that would break according to the presenter. Not in the presentation obviously, but there' the entire fight between Microsoft and the antivirus industry over this as well.
My impression is that they indeed did some significant work. Esp. the work to make it easier to run without local admin rights seems a major step forward.
They also left out some easy to achieve things that would make the world a lot safer. E.g. IE7 doesn't make it any harder to see a https site with a bad ssl certificate. Just pressing next still accepts the bad cert and shuts up about it. This makes man in the middle attacks way too easy.
I'm worried about the confidence they have this will be enough to change the tide. And most of all, I'm worried about the added complexity, as complexity creates more (security) bugs in my experience.

So: make up your own mind and let us know in the poll.

--
Swa Frantzen -- Section 66
Keywords: Microsoft vista
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