IT Baseline Protection Manual - The Information Warfare Site

Threats Catalogue Deliberate Acts Remarks
____________________________________________________________________ .........................................
T 3.27 Improper time synchronisation
Novell Netware 4.x allows several servers to interact within a network. To
ensure smooth operation of network services, for example, for the creation of
date and time stamps of files, review and auditing, and to guarantee time
restrictions for login procedures, it is very important for all servers to indicate
the same time of day. Changes to a directory tree also carry a time stamp in
Novell Netware Version 4; which determines the processing sequence when
the NDS is updated. For this reason, it is important to maintain identical times
for all Netware 4 servers in a network.
Potential threats:
- If the internal hardware clock of a computer is not checked and, if
necessary, adjusted prior to an installation of a Netware 4 server on that
computer, it might not be possible for the new server to match itself with
the remaining Netware 4 network, thus giving rise to the danger of the
NDS malfunctioning.
- If the time source fails within a network which uses the single-reference
procedure for time synchronisation, a replacement time is no longer
available. This allows uncontrolled changes to file access rights and object
access rights.
- NDS modifications whose time stamps lie far ahead in the future due to an
incorrect system time are only executed on the actual attainment of these
future deadlines. This might result in errors and problems which are hard
or impossible to comprehend, due to the large time span between the issue
and execution of the modifications.
- If, after the installation of the server, a radio clock is connected without
prior deactivation of the automatic switch between summer and winter
time, this will result in an additional adjustment by one hour.
____________________________________________________________________ .........................................
IT-Baseline Protection Manual: Oktober 2000