7. Global file sharing and inappropriate information sharing via NetBIOS and Widnows NT ports 135->139 (445 in Windows 2000), or UNIX NFS exports on port 2049, or Macintosh web sharing or AppleShare/IP on ports 80, 427, and 548
The above listed services allow for directories and files to be shared over a network.
Versions Effected: UNIX, Windows and Macintosh systems are effected.
CVE Entry: CAN-1999-0520, CAN-1999-0554
Details: While file and directory sharing is a service that is required on most networks care should be taken when setting up shares on Internet exposed systems. NetBIOS, used in Microsoft Windows operating systems to facilitate file sharing also exposes other possibly sensitive data including but not limited to user and group information, machine names, last logon dates, and password policy information.
Recommendations: When sharing mounted drives, ensure only the required drives are shared. Some experts recommend also limiting access to these drives by IP address. Windows hosts should be have file shares protected by strong passwords and user access control lists. Special care must be taken when using the "everyone" group under Windows NT. Also under Windows NT, the Restrict Anonymous registry key should be implemented. For Macintosh systems, disable file and internet file sharing extensions unless required. If required, ensure strong passwords are used.
Additional Information:
http://www.sans.org/topten.htm