Vista and SpamButcher - The Joy of Security Elevation (Part 1)

I'd mentioned previously that our first round of testing indicated SpamButcher worked fine on Windows Vista. I'd also eluded to some problems we found in subsequent testing.

In the first batch of tests I installed Vista on a new computer. I then installed SpamButcher. Vista prompted if I wanted to give an application (SpamButcher setup) special permission to modify the system. I said, "Yes" - and everything seemed to go normally.

There was no question it looked a little, "funny." The scroll bars didn't line up properly and a few other things just didn't look quite right.

However, more importantly the anti-spam functionality seemed to work. I ran through all the basic functionality without experiencing anything unusual. I concluded that we'd eventually need to do some visual cleanup - but Vista users would probably expect a lot of existing applications to not quite render perfectly in the new environment.

A few months later I'd setup another Vista system and performed the same tests again. Again, everything seemed to go fine - at first.

I downloaded SpamButcher, started the installation process. Vista prompted for an administrative account - so I gave it one. SpamButcher then continued to setup. After installing, SpamButcher spam tool launched and detected my account information.

SpamButcher again passed all the basic functionality tests. I sent it some test spam, and it caught it. Message preview and recovery also worked fine.

Then, I manually restarted SpamButcher. To my shock - all the configuration information and blocked mail had vanished! Houston, we have a problem.

It took me a while to figure it out, but there was one key difference between the first Vista test and the second one.

In the first test I had installed SpamButcher running as an administrative account.

In the first test I had installed SpamButcher running as a non-admin account.

When you try to run a setup program on Windows Vista from a non-admin account, it prompts you to enter credentials for an account with administrative privileges. This feature is called UAC security elevation.

The gotcha is that the setup program then runs in the context of the user with administrative rights. This includes any tasks that the setup program launches. In our case, setup was launching SpamButcher at the end of installation.

This means that any configuration done by the user to SpamButcher during the first run was actually being done to the admin account's profile, not theirs! When the user turns around and runs SpamButcher again, any settings they changed or spam they caught would vanish!.

The good news is that when you setup Vista - the first account created defaults to having administrative privileges. So most users won't hit the problems.

However, if Windows Vista is deployed in a corporate domain environment, default domain accounts commonly don't have admin rights.

With Windows XP or 2000, SpamButcher simply refuses to install unless you're running as an administrator. This is common practice.

Rest assured, everything has been fixed in the latest version. In the next article I'll get into how we dealt with this problem.

(On to Part 2...)

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