Archive for February 2013

XProtect Updater Redux

February 8, 2013

In the past 24 hours, Apple has released an update to the XProtect malware definitions. If your Macs have received the latest XProtect definitions, Adobe Flash Player will be blocked unless it is the version current as of yesterday (11.5.502.149).

If you have already updated your clients to that version of the Flash Player, good for you!

If you don’t want to be surprised by this sort of thing and have to scramble to address it, might I point you here?

Disabling iCloud as default save location

February 5, 2013

icloud-logo
Krypted.com has a new post on disabling iCloud as the default save location for new documents.

This feature affects apps that can save to iCloud, and only if the user has an iCloud account configured for the current login.

Still, you might want to turn this off by default for all users in your organization so they don’t accidentally store company documents on Apple’s servers. The Krypted.com post shows a command-line way to change this setting for a single user. How might you do this for all users?

One way would be to install a computer-level profile that installs the right settings. Here’s one.

If installed as root using the /usr/bin/profiles tool:

sudo profiles -I -F DontSaveNewDocumentsToiCloud.mobileconfig

This setting will be applied Once to all users as they login.

DontSaveNewDocumentsToiCloud.mobileconfig was created using Tim Sutton’s mcxToProfile tool.

Still more on the XProtect Updater

February 4, 2013

Mike Boylan writes in a reply to my previous post:

…I have to respectfully disagree that disabling the auto-update mechanism for Xprotect should be done in organizations with managed machines. Do you disable the automatic update mechanism for your anti-virus software? Do you manually test every definition update and push each one out through Munki? I’d assume not. Xprotect (clearly) isn’t serving the same type of updates as Apple software update. It’s a malware prevention/blocking (and in some cases, removal) system. I won’t argue that Xprotect’s disabling of Java plugins will almost certainly have a larger impact across organizations than say something like a Sophos definition update, but nonetheless, the intent is still to protect systems. Xprotect and anti-virus software together are meant to serve complimentary roles. These Java plugins are being disabled because serious known exploits are being used in the wild. For a company that cannot function without version xyx of the Java plugin, does it make sense to make changes so that it can continue to operate effectively? Sure. But I doubt most organizations rely that heavily on a single plugin. Also, how many different types of updaters should we as admins be responsible for managing? There are already too many. For most admins, I don’t think it’d be a responsible decision to add Xprotect to the list.

Mike:

If Xprotect’s disabling of web plugins has not caused your organization any issues, or you are willing to react to any issues such disabling might occur in the future, it may well make sense to leave things as they are for your organization.

In my organization, the Java 6 web plugin is required to perform vital, daily business functions. When it doesn’t work, business functions are seriously impacted.

My argument might be subtle.

Apple is acting as systems administrator for machines by updating the XProtect plists. As long as you are content to let Apple make those changes, and won’t complain if Apple makes a change that breaks things for you, by all means, leave the XProtect updater mechanism alone.

If, on the other hand, _you_ are taking responsibility for managing your machines, making sure they are functional for your organization, and keeping them safe from malware, you’ll want to disable _Apple’s_ update of the XProtect malware definitions, and take over updating them yourself.

If you do not want to be surprised that one morning Java or Flash or some other plugin has been disabled on all the Macs you manage, you cannot let Apple update these definitions without your review. You must take responsibility for reviewing and implementing Apple’s changes, or a modification thereof.

Is this more work? Yes. Does it add risk to your organization? Probably. All security is a trade-off between functionality and protection. Malware protection that prevents my users from doing their work is not an acceptable trade-off. Apple has made one decision about the trade-offs, one that protects a great number of Mac users while negatively affecting a very small number of them. That is not the correct decision for my organization.

The only way I can ensure the correct decisions are made for my organization is to not leave the decision making process solely to Apple, but to instead review Apple’s changes and alter them if needed for the benefit of my organization.

Each organization needs to weigh this decision for themselves.

More thoughts on XProtect Updater

February 1, 2013

I’ve been thinking more about Apple’s Xprotect Updater mechanism in light of the recent updates that have disabled Java web plugins. See yesterday’s post, for example.

In many enterprise environments, admins choose to run their own Software Update server to provide Apple updates. This is done for several reasons. One is to save bandwidth — it’s more efficient for a single machine to download available Apple updates over your Internet connection, then have all the other machines get those updates over the local LAN.

But another reason is to be able to control which updates are offered to your managed computers. Apple may offer an update that causes issues in your organization. For example, we did not deploy the “Java for OS X 2012-006″ update in our environment because it disabled the Java 6 Web Plugin, which we needed.

Yesterday’s Xprotect update essentially did the same thing, this time over a wider range of machines. I quickly put together a workaround, but one of the things the workaround does is to turn off the automatic updates of the XProtect data.

After thinking more about the ramifications of this, I think that this is exactly what most enterprise sites should do. They should treat this update mechanism like all other update mechanisms. I think you should turn this off on most or all of your managed machines.

“But wait,” you are thinking. “Isn’t this risky? Apple is trying to protect users from malware.” If you only turned off the update mechanism on all your machines and did nothing else, you are adding risk. But what you should do is something similar to what an admin that vets Apple Software Updates (or third-party application updates) does before releasing them.

You should enable the update mechanism on an admin machine. When there are new XProtect.meta.plist and/or XProtect.plist files, you should test to see that they don’t cause any issues in your organization, modifying them if needed. You can then use your favorite software deployment system (I like Munki) to distribute these files to your managed machines.

In this way, your managed machines can still get the benefit of updates to Apple’s malware protection mechanism without risking that a component vital to your organization will be blocked without warning.


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