If your job includes security, the Security Configuration
Editor in SP4 can truly make things much easier. In this
new column, an NT security expert tells what the new release
can do for you.
Inside Service Pack 4
If your job includes security, the Security Configuration
Editor in SP4 can truly make things much easier. In this
new column, an NT security expert tells what the new release
can do for you.
- By Roberta Bragg
- January 01, 1999
Whats the best server? Rightthe one thats
up 24 x 7 x 365. Attention to security is one way to keep
it there. As administrators, managers, integrators, developers,
and trainers were responsible for making others
aware of security issues. We dont want to be among
the 75 percent of companies that a 1997 Computer Security
Institute study lists as having lost money to computer
crimes. We dont want our computer systems to be
harmed by attacks this year.
Thats why MCP Magazine and I would like
to welcome you to Security Advisor, a monthly
column that explores security as it applies to your enterprise.
You probably already lock your doors at night; well
show you how to lock your network. In coming months, we
plan to look at many different aspects of security, from
conducting a security audit to the special concerns and
techniques of ensuring security on BackOffice products.
This month, well examine the increased security
offered by Service Pack 4 for Windows NT 4.0.
An Awareness of Security
A lot has changed since Service Pack 3 for Windows NT
4.0 was introduced in May 1997. At that time, there were
fewer NT boxes in large organizations, and fewer of us
were focused on security issues. The network philosophy
seemed to be, If it aint broke, dont
fix it.
With earlier releases of NT, Microsoft often appeared
to be on the defensive, denying security issues while
preparing fixes for only the most notable ones. With the
growing acceptance of NT, thats changed. Today,
Microsoft has a Web sitewww.microsoft.com/securitydedicated
to security issues. When a new NT problem is reported,
the company appears to move into action, rapidly verifying
or reassuring, explaining, offering a hot fix, and making
recommendations. You can even sign up for Microsoft security
bulletins, delivered by e-mail.
While only a few of the 300 bug fixes in SP4 actually
address security issues, what you will find in it is the
Security Configuration Editor (SCE). Designed to be a
part of NT 5.0, the SCE integrates security implementation
and analysis on NT, thereby addressing a fundamental weakness
of the OS. [This article is based on a beta version
of SP 4.Ed.]
Snap-in Security
I used to wonder why my students complained about the
lack of NT security. Theyd pose a problem and Id
answer with instructions on how to use NTFS, how to set
up rights and permissions, and how to turn on auditing.
Simple, from a classroom stanceand if youre
in a small domain. But more and more of my students were
coming from companies implementing huge enterprises with
dozens of NT servers and hundreds of NT workstations.
They didnt want to hear, First enable file
and object auditing in User Manager for Domains, then
visit folders and files in Windows Explorer to turn on
auditing for files and folder, then use Printers to turn
on auditing for printers, then edit the NT Registry, then...
They wanteddemanded, evensomething more central
and less time-consuming and confusing. Some bought third-party
solutions. Others just didnt implement any security
beyond logon.
The Security Configuration Editor is a Microsoft Management
Console snap-in utility that lets you centrally administer
security features across a Windows NT domain. It doesnt
replace the current set of utilities for adding users,
establishing object permissions, and auditing; although
you can do all of these tasks in the new editor, you can
still use other utilities as well. SCE simplifies the
implementation of security features and provides an analysis
component that detects variations from the policy set.
Security configuration is made in the large and implemented
in the background. Analysis provides information about
the compliance to policy.
Install
Service Pack 4 Right the First Time |
To download a copy of Service
Pack 4, go to www.microsoft.com/ntserver/default.asp,
click on Downloads, and select Service
Pack 4.
Before Installing Service
Pack 4
1. Update system Emergency Repair Disk
using rdisk /s.
2. Perform a full backup including
the registry.
3. Disable nonessential third-party
drivers and services not required to
boot the system.
4. Contact OEMs for updated drivers.
5. Install Internet Explorer 4.01 or
register Protected Storage by issuing
the command storesinstall command.
6. Visit www.systemsoft.com
for information if youre running
SystemSofts Cardwizard for Windows
NT (support for PCMCIA) or PowerProfiler
for Windows NT (support for Advanced
Power Management). Your system may fail
to boot if you dont follow the
specific procedures outlined at this
site. Microsoft recommends that you
remove . advanced power management settings,
programs, utilities; make sure theyre
not being used before installing the
service pack.
The Actual Installation
1. Navigate to the folder containing
the Service Pack file.
2. Change to the folder \I386 or \ALPHA
(depending on your CPU).
3. Type UPDATE.
4. Follow the instructions.
If, while installing Service Pack 4,
a Web page opens in your browser, do
the following:
1. Click Windows NT Service Pack.
2. Click Install Service Pack.
3. When asked if you wish to open or
save file Spsetup.bat to disk, select
Open.
4. Follow the instructions on screen.
If you change or add new software or
hardware components after installing
Service Pack 4, you must reinstall the
service pack.
Uninstalling Service Pack
4
1. Open Control Panel.
2. Click on Add/Remove Programs.
3. Select Service Pack 4.
4. Click the Add/Remove button.
Note: samsrv.dll and winlogon.exe arent
overwritten. Service Pack 4 changes
the Security Account Manager Database,
and older versions will no longer recognize
the structure. If you reapply earlier
service packs after uninstalling Service
Pack 4, answer no to the
Confirm File Replace dialog
boxes for these two files. Otherwise,
you wont be able to log onto the
system.
Roberta Bragg, MCSE, MCT
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Installing SCE
Installation of SCE is straightforward. After installing
Service Pack 4, follow these steps.
1. Run the Microsoft Management Console. (Click Start
| Run and type mmc, then press Enter.)
2. From the Console menu, click Add/Remove Snap-Ins.
3. Click Add.
4. Select Security Configuration Editor.
5. Click OK.
Security Configuration Areas are subdivisions of system-wide
security configurations. Table 1 shows the currently defined
areas.
Table
1. Security Configuration Areas |
|
Security area |
Interface items |
Function |
System Security Policy |
Password Policy,
Lockout Policy, Audit Policy, User Rights
Assignment, Security Options |
Set access policy,
password policy, overall object security,
audit settings. |
Rights and Privileges |
User Groups
Not present in early
beta. |
Local and Domain
security policy attributes. |
Restricted Groups |
Restricted Groups |
Assign group memberships,
privileges, and rights. |
System Services |
System Service |
Group membership
for sensitive groups such as administrators,
power users, print operators, server operators,
and domain administrators. |
System Registry |
Registry |
Configure services
including TCP/IP, NetBIOS, file sharing,
and printing. |
System Store |
File System |
Set Access Control
Lists on Registry Keys. |
Directory Objects
Not present in early
beta. |
Directory Objects |
Set security for file volumes
and directory trees. Active Directory
(with NT 5.0) |
|
|
SCE was developed to support additional elements. Because
configuration information is stored in a standard .INF
file format, it can easily be modified by those who understand
this format. For instance, software vendors who write
services can extend the system services component
to include their own. Security can thus be configured
on an ISVs service, and the ISV can be sure that
any analysis performed will included its own service.
A Simple Interface
The SCEs Explorer-like user interface is simple
to navigate (see Figure 1).
|
Figure 1. The Security
Configuration Editor. The left pane holds configuration
and inspection folders; the right pane shows objects
to be kept secure or actual attributes of an objects
security configuration. |
The left pane includes top-level folders for Configuration/Inspection
Templates and Last Configuration/Inspection.
You can expand these folders to show greater detail on
each template and security area. The right pane exposes
the objects , and when you view an analysis, it also exposes
departures from the security policy.
Context menus are available to perform configuration
assignment; security analysis; and for identification
of and making changes to objects, rights, privileges,
and services.
The SCE includes sample templates for defining your security
policy. You can modify the existing templates or, as Ive
mentioned, define your own (through the .INF files). You
can make Security Configuration Area settings on your
domain by selecting a template in the tree view under
Configuration /Inspection Templates and then
right-clicking on the template and selecting Assign
Configuration from the context menu.
When youve selected and assigned a template, its
security configuration becomes the security configuration
for the local machines as well as for some parts of the
domain (system services and restricted groups). For example,
members of the Administrators group who arent identified
in the policy are removed from the Administrators group
and logged to the configuration log.
Changing template configurations to get the policy that
is right for you is as simple as pointing and clicking.
Double-clicking on an object exposes dialog boxes that
allow you to view and edit the current configuration.
Most boxes appear to be exact replicas of the more familiar
tools such as Add Users and Groups or easily
discernable variations like Maximum Password Age.
If youre already familiar with current configuration
tools, youll have no trouble with SCEs interface.
Security Analysis
To analyze security, right-click on the Last Configuration/
Inspection and Click Perform Analysis. A pop-up window
tracks your progress. When the analysis is complete, you
can view the results in both a log (see Figure 2) and
by traversing the Last Configuration/Analysis
branch.
|
Figure 2. A fragment of
the text log for an analysis of user rights. |
Another nice feature that SCE provides is an Analysis
Viewer that shows each template recommendation next to
current settings. It also highlights problem areas with
different fonts and colors. You can correct problems in
the view by changing the recommended settings. If you
do correct problems in this way and then select the reconfiguration
option, the correction will be made to the object. The
Analysis Viewer is more than a way to view
problems. Problems can be fixed without leaving the viewer.
Not All Is Perfect
Hold on, though. SCE isnt necessarily the final
solution. Imagine this scenario. Administrator A gets
tired of repeated demands from User1 for more permission
on the system, so she makes User1 a member of the Administrators
group. Administrator B, who is the Auditor, runs a security
analysis and discovers that this unknown Administrator,
User1, exists. Administrator B removes this administrator
from the Administrators group and makes a note to chastise
Administrator A. Meanwhile User1 cant install the
latest whiz-bang utility and hollers at Administrator
A, who puts him back in the Administrators group. You
can only imagine the NT Administrator privilege war that
would develop as each Administrator tries to gain control.
The bottom line: If authority is distributed, maybe you
shouldnt install SCE.
Along with ease of implementation and administration
in NT, theres definitely a need for policy control
and maintenance. In environments where authority is distributed,
SCE shouldnt be installedor contentious issues
should be excluded from analysis (unless youve already
resolved them).
Security-Related
Bug Fixes in Service Pack 4 |
Fixes in Service Pack 4
correct the security-related problems
outlined below. For additional information
on a specific fix, check out Knowledge
Base articles available from Microsofts
TechNet site (www.technet.microsoft.com)
or on the Knowledge Base CD thats
part of a TechNet subscription.
Q129457 Restrict
Anonymous
Service Pack 3 introduced the capability
to control anonymous access to system
information. If Service Pack 3 is installed
and RestrictAnonymous is enabled, anonymous
connections can obtain the password
policy.
Q142047 Access Violation
DNS
A modified DNS query has the AnswerCount
field greater than 0. This means that
the data from the question should be
present, but it isnt. As a result,
an access violation occurs and stops
the DNS service.
Q143478 Out of Band
Data
Senders set the URGENT bit flag in the
TCP header to an incorrect size. The
flag indicates where urgent data ends
and normal data begins. If no normal
data follows this pointer, Windows NT
may crash. The OOB data attack (as it
has been called) was addressed in Service
Pack 3; however, this updated fix handles
variations of the original attack.
Q143484 Large IIS
Request
Microsoft Internet Information Server
2.0 and 3.0 service stops if it receives
a request (URL or header) of four to
eight kilobytes of data from a browser.
Q146945 and Q171777
GetAdmin
A normal user can be granted administrative
rights if this program is run from the
PDC or workstation.
Q154460 Denial of
Service-Simple TCP/IP
If simple TCP/IP services is installed,
a flood of UDP datagrams sent to the
subnet broadcast address port 19 (chargen-character
generator) generates a response to each
broadcast. The result is a flood of
UDP datagrams, increased bandwidth utilization,
and decreased performance.
Q165005 Land Attack
SYN packets with the same source and
destination address are sent to a host.
These packets look like they were sent
by the host to itself. The host will
slow down temporarily while it tries
to respond to itself.
Q167629 DNS Predictable
Query
Cache pollution (saving the incorrect
IP of a query in the DNS cache) is accomplished
by knowledge of the series of IDs used
in recursive queries. The attacker spoofs
responses to DNS queries, filling up
the cache with incorrect responses,
for example, responding that microsoft.com
is IP 127.0.0.1.
Q169461 Malicious
Telnet Attack
A flood of characters is directed at
the DNS service port, causing DNS to
stop. This interrupts name resolution
services. Its caused by a telnet
session.
Q173059 Security
Events Not Logged During Audit
User and Group Management events should
be logged if audit policies are set.
Some event IDs (for example, Event ID
640: General Database Changea
change made to the SAM database, Event
ID 629: User Account Disabled) werent
recorded.
Q174551 TCP/IP Advanced
Security
The Advanced Security option of TCP/IP
properties on the RAS server clears
automatically after RAS clients dial
into the Windows NT RAS server. Thus,
advanced security options arent
in effect.
Q179129 Modified
TearDrop
Service Pack 3 provided a solution to
the TearDrop Attack. A modified version
of the TearDrop attack sends IP fragments
that, when reassembled, form an invalid
datagram. The second packet overwrites
data in the UDP header. The datagram
is incomplete. Kernel memory is allocated
and, if enough invalid datagrams are
received, the system may crash.
Q180963 Denial of
Service
An incorrectly formulated Server Message
Block (SMB) logon request can cause
memory corruption, OS hang, or restart.
The logon request at fault here has
the incorrect data size indicated.
Q182918 Account
Lockout
An account is locked out at the domain
controller if a users incorrect
password attempt reaches the Bad Logon
Attempts limit. If the workstation has
enabled auditing, an account lockout
event is generated at the workstation
but not at the domain controller. This
fix will generate an audit event at
the domain controller that handled the
logon request.
Roberta Bragg
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The Master at Managing Security
Is Service Pack 4 really a Security Pack 4? In some ways,
yes. It has many elements that you can use to improve
Windows NT 4.0 security. Can is the key word here. Bug
fixes, security editors, and analyzers wont work
if you dont know how to use them. Will Service Pack
4 solve all your problems? Nope. Will it create some new
ones? No doubt. Do I recommend installing it? You bet!
It takes the pain out of downloading, understanding, and
applying numerous hot fixes, and it has created an answer
to one of my most compelling annoyances: managing security
in NT. SCE centralizes many of the more meddlesome aspects
of security maintenance and shows promise of more to come.