The remote host is missing an update to samba announced via advisory USN-702-1.

The problem can be corrected by upgrading your system to the following package versions: Ubuntu 8.10: samba 2:3.2.3-1ubuntu3.4 In general, a standard system upgrade is sufficient to effect the necessary changes. https://secure1.securityspace.com/smysecure/catid.html?in=USN-702-1

Gunter Höckel discovered that Samba with registry shares enabled did not properly validate share names. An authenticated user could gain access to the root filesystem by using an older version of smbclient and specifying an empty string as a share name. This is only an issue if registry shares are enabled on the server by setting registry shares = yes, include = registry, or config backend = registry, which is not the default.