Almost everyone knows that when you set up a share on a Windows 2000 workstation or server, you should set the permissions to restrict access. But most administrators don't bother to change the cache settings. These settings aren't particularly dangerous, but you should understand what they do.
The cache settings store a copy of documents accessed through the share in a special directory on the client hard drive. This works just like the cache in Internet Explorer that allows you to look at web pages that you've previously visited, even when you aren't connected to the network. Using the share's cache, a user can use documents from the share when there is no network access.
While this isn't particularly dangerous, the shares do necessarily copy documents that are potentially sensitive and put them in a directory on the client's workstation, typically a laptop, that most users have no idea exists. Thus, it's possible for users to be less careful about their security if they believe the only copy of the documents exists on a well-protected server.
The default setting on a share is to enable caching, but restrict it to manual initiation. Thus, users would have to explicitly tell their computer to cache the documents. This is fairly safe, but you may want to disable caching for your shares, or at the very least, educate your users. Disable caching by right clicking on the share and selecting properties, then caching.
Thomas Alexander Lancaster IV is a consultant and author with over ten years experience in the networking industry, focused on Internet infrastructure.
This was first published in December 2002