MCP 70-299 : Deploying andTroubleshooting IPSec

Lesson 1: Deploying IPSec

Deploying IPSec by Using Active Directory :

If your organization has an Active Directory domain, you should almost always use Active Directory to deploy IPSec. The primary tool for building IPSec policies is the graphical user interface provided by the IP Security Policy Management snap-in. You can use the IP Security Policy Management snap-in to create, modify, and activate IPSec policies, and then assign them to a domain, site, or organizational unit (OU) in Active Directory by using the Group Policy Object Editor snap-in.

If you decide to deploy IPSec policies by using GPOs, you must understand how IPSec policies differ from other types of security settings. Most settings in a security template can be combined by importing them into a single GPO. If multiple GPOs with overlapping settings are assigned to a single computer, the computer will automatically resolve any conflicting settings. Because multiple security templates and sets of Group Policy settings can be applied to a single computer, role-based security templates work perfectly when a computer serves multiple roles.

Only one IPSec policy can be applied to any single computer. If multiple GPOs assign multiple IP security policies to a computer, only the GPO with the highest precedence will be applied. IPSec policy uses the same precedence sequence as other Group Policy settings, which is from lowest to highest: Local GPO, site, domain, OU.

Deploying IPSec Using Scripts :

If a computer is not a member of a Windows 2000 domain or a Windows Server 2003 domain, it cannot retrieve IPSec policy from Active Directory. However, as Chapter 8 described, you can use the Netsh, Ipseccmd.exe, and Ipsecpol.exe command-line tools to create IPSec scripts. You can then include these scripts as startup scripts for each computer on your network. You can use Ipsecpol.exe only on computers running Windows 2000, Ipseccmd.exe only on computers running Windows XP, and the Netsh commands for IPSec only on computers running Windows Server 2003.

Although having three separate scripting tools for the three operating systems makes managing a typical network challenging, the three tools are similar in functionality. Although the exact parameters vary, each tool provides separate static and dynamic configuration modes and the ability to display existing IPSec configuration information. For each tool, the dynamic configuration mode changes the currently running IPSec settings, although static configuration mode changes the persistent configuration. In other words, dynamic configuration changes are lost after you restart your computer,but static configuration changes will remain.

Deploying Certificate Services for IPSec :

Although Kerberos is the simplest way to authenticate IPSec peers, certificates provide greater flexibility for authenticating non-Windows IPSec peers and other computers that are not members of an Active Directory domain. In Windows 2000 and Windows Server 2003, you can use Certificate Services to automatically manage computer certificates for IPSec authentication. IPSec also supports the use of a variety of non-Microsoft X.509 public key infrastructure (PKI) systems. Windows Server 2003 IKE has basic compatibility with several certificate systems, including those offered by Microsoft, Entrust, VeriSign, and Netscape. If you are using a non-Microsoft PKI system, the PKI
system must be able to issue certificates to computers and store their certificates in the Windows Cryptographic Application Programming Interface (CryptoAPI) computer certificate store.

IPSec’s use of certificate authentication is compatible with many different PKI architectures, and IKE places relatively few requirements on the contents of a certificate. Typically, computers that have a common trusted root, or whose certificates can chain through a cross-certification trust relationship, can successfully use certificatebased authentication for IPSec. To use certificates for IPSec authentication, you define an ordered list of acceptable root certification authority (CA) names in the
authentication method.

MCP 70-299 : Assessing and Deploying a Patch Management Infrastructure

Lesson 3: Deploying Updates on Existing Clients

Manually Applying Updates :

Microsoft distributes updates by using executable files that automatically install themselves when run. However, all Microsoft updates also support standardized commandline parameters to change the default installation behavior. Table 6.3 lists the parameters available for updates. The parameters listed in the New Parameter column can be used with updates released on or after September 17, 2003. You must use the parameters listed in the Old Parameter column for updates released prior to September 17, 2003. As of the time of this writing, new updates support the old parameters. However, backward compatibility with the old parameters might be dropped at some point, so you should always use the new parameters when possible.

Windows Update Web Site :

The quickest way to manually detect missing updates and install them on a computer is to directly access the Windows Update Web site. To update a computer with critical updates, security updates, and service packs by using Windows Update:
1. Click Start, point to All Programs, and then click Windows Update.
2. Click Scan For Updates.
3. Click Review And Install Updates.
4. Click Install Now. The updates will be downloaded and installed. You might be prompted to accept
a license agreement.
5. Restart the computer and return to step 1 until all critical updates and service packs have been installed.

Software Update Services :

SUS, a free download that can be installed on Windows 2000 Server–based and Windows Server 2003–based computers that have Internet Information Services (IIS) installed, provides administrators with a local alternative to the Microsoft Windows Update servers. Using the Automatic Updates client, computers on your network can automatically download and install updates from your SUS server.
The easiest way to install IIS is to use the Manage Your Server tool and add the Application Server role. For the purposes of installing Software Update Services, you can accept the default settings; neither Microsoft ASP.NET nor Microsoft FrontPage extensions are required. SUS will install itself into the Default Web Site, if it is available. Otherwise, SUS will create a new Web site.

Group Policy :

Group Policy objects can be configured to automatically install Windows Installer packages on computers. Service packs include a Windows Installer package, making it simple to use a Group Policy object to deploy a service pack.
Service packs, more than any other type of update, require extensive testing and pilot deployments because of the extensive changes they make. Although SUS is an excellent way to distribute frequently released security updates to a large number of client computers, you cannot use a single SUS server to stage a pilot deployment to a small number of computers in your organization. Fortunately, you can use Group Policy objects to distribute service packs directly.

After you assign the service pack package, Windows Installer installs the service pack automatically when users start their computers. Users are not presented with a choice to install the service pack. Only a network administrator or someone who is logged on to a local computer as a member of the Administrators group on that computer can remove the assigned software.
To distribute a service pack by using a Group Policy object:
1. Download the network install version of the service pack to a file server.
2. Extract the service pack files using the /x parameter. For example, to extract Service Pack 4 for Windows 2000, execute the command W2ksp4_en /x. Extract the files to a shared folder that both client computers and domain controllers can access. After the extraction completes, click OK.
3. Connect to the shared folder just as a client would. For example, if you extracted the files to the \\server\updates shared folder, map a network drive to \\server\updates. This will ensure that clients can locate the package after the GPO instructs the client to install it.
4. Create a new GPO or edit an existing GPO that you will use to distribute the service pack.
5. Using the Group Policy Object Editor snap-in, expand Computer Configuration, expand Software Settings, and then click Software Installation.
6. Right-click Software Installation, click New, and then click Package.
7. Navigate to the folder to which you extracted the service pack, and locate the Update.msi file. Though future service packs might place this file in a different location, recent service packs have stored it in the i386\update\ directory. Click the Update.msi file, and then click Open.
8. In the Deploy Software dialog box, click Assigned, and then click OK.

After a package has been added to the Software Installation node of a GPO, you can choose to remove or deploy it for troubleshooting purposes. If a service pack installation fails to deploy successfully, you can redeploy it by right-clicking the package, clicking All Tasks, and then clicking Redeploy Application.

MCP 70-299 : Assessing and Deploying a Patch Management Infrastructure

Lesson 2: Deploying Updates on New Clients
Security Considerations :

Computers are under attack from the moment they connect to the Internet. Worms and viruses are constantly active, probing every IP address for vulnerabilities. Microsoft Windows Server 2003 is much more resilient to attacks that might occur during the installation process than earlier versions of Windows because it adheres to the “secure by default” ideal. However, vulnerabilities have been discovered in unpatched computers running Windows Server 2003, and these vulnerabilities might be exploited during the setup process.
Although it is possible to update and secure a computer running Windows so that it can be connected directly to the Internet without becoming infected by a worm or a virus, a computer does not have the benefit of updates or security hardening during the installation process. If you attempt to install Windows on a computer while it is connected to the Internet, there is a high probability that it will be attacked, and possibly exploited.

Integrated Installation :

You can apply service packs, but not necessarily other types of updates, directly to Windows 2000, Windows XP, and Windows Server 2003 installation files. The process of integrating a service pack into the original setup files for an operating system is called slipstreaming. Slipstreaming creates an integrated installation—including the latest service pack—that can be used when installing the operating system on new computers. Using this process improves the security of new computers, and reduces the time required to apply updates after completing the initial installation. You can either perform the installation from a shared folder or create a CD with the integrated setup files.
Because the integrated installation replaces individual files, the space requirements for this installation type are almost identical to the space requirements for the base operating system. After you slipstream a service pack into the operating system setup files, you cannot remove the service pack.

Lesson Summary :

■ Computers should not be connected to the Internet or even to a private network with other hosts, until after the operating system and all updates have been installed.
■ Computers can be built while connected to the network if you create an isolated network segment with a minimal number of trusted computers that have been scanned for worms, viruses, and other malicious software.
■ You can reduce the time required to install new updates by slipstreaming a service pack into operating system installation files and configuring other updates to be automatically applied.

MCP 70-299 : Assessing and Deploying a Patch Management Infrastructure

Lesson 1: Assessing Patch Levels

The MBSA Console :

Microsoft Baseline Security Analyzer (MBSA), which was also discussed in Chapter 4, is used to analyze one or more computers for vulnerabilities in two categories: weak security configurations and missing security updates. This section focuses on using MBSA to scan for updates that should have been installed but have not been.
After installing MBSA, you can use it to scan all computers on your network or domain for which you have administrator access. To scan all computers on a specific subnet using your current user credentials:
1. Start MBSA by clicking Start, pointing to All Programs, and then clicking Microsoft Baseline Security Advisor.
2. On the Welcome To The Microsoft Baseline Security Analyzer page, click Scan More Than One Computer.
3. On the Pick Multiple Computers To Scan page, type the IP address range you want to scan. To speed up the scanning process, clear all check boxes except for Check For Security Updates. If you have a Software Update Services (SUS) server on your network, you can further speed up the process by selecting Use SUS and specify
4. Click Start Scan. As MBSA performs the scan, it will keep you updated on the progress,
5. After the scan is completed, the View Security Report page appears, listing the computers that were scanned.

MBSACLI :

Scanning a large network should be done on a regular basis to find computers that have not been properly updated. However, scanning a large network is a time-consuming process. While the MBSA console is the most efficient way to interactively scan a network, the Microsoft Baseline Security Analyzer command-line interface (MBSACLI) provides a way to script an analysis. By using scripts, you can schedule scanning to occur automatically, without your intervention. In this way, you can have MBSACLI generate a report that you can refer to on demand.
Another good reason to schedule scans by using MBSACLI is to scan from multiple points on your network. For example, if your organization has five remote offices, it is more efficient to scan each remote office by using a computer located in that office. This improves performance, reduces the bandwidth used on your wide area network, and allows you to scan computers even if a perimeter firewall blocks the ports that MBSACLI uses to scan.

Lesson Summary :

■ The graphical MBSA console is the most efficient way to scan a single computer or multiple computers for the presence of updates.
■ The graphical MBSA console can be configured to scan a single computer, a range of IP addresses, or all computers contained within a domain.
■ MBSA stores reports in XML format in the C:\Documents and Settings\username\SecurityScans folder by default. At any time, you can view these reports by using MBSA.
■ MBSACLI provides a command-line interface to MBSA’s scanning functionality. MBSACLI functions in two modes: standard MBSA mode and the backward compatible HFNetChk mode.
■ Scanning a large number of computers can take several hours and consumes significant network resources. Therefore, you should schedule the scanning to occur after business hours by using the command-line tools.

3 - Hardening Computers for Specific Roles :

Lesson 1: Tuning Security for Client Roles :

Planning Managed Client Computers :

When planning the requirements for managed client computers, start by identifying the baseline security level that is appropriate for users to have on their computers. The baseline user security level is specified by granting users membership to one of these groups: Users, Power Users, and Administrators. Membership in the Users group gives the most protection from a number of external threats, such as viruses, and it limits the damage that users can accidentally or intentionally cause to their computers. However, user level permissions have the most incompatibility problems with older applications. Take particular care before you give users privileged access to computers that they
share with other employees.
Next, identify the types of systems users need to interoperate with. Interoperability with earlier systems, such as Microsoft Windows NT 4.0–based servers and UNIX file servers, necessitates that some of the security you might use in a pure Windows Server 2003 environment must be relaxed.
Finally, consider the level of support users provide for their own computers. Users who use portable computers and provide their own support might require administrator rights on their computers. Other high-performance users, such as developers, might also need administrative rights.

Software Restriction Policies :

Software restriction policies are a feature in Windows XP and Windows Server 2003 that can be used to regulate unknown or untrusted software. Businesses that do not use software restriction policies put the burden of identifying safe and unsafe software on the users. Users who access the Internet must constantly make decisions about running unknown software. Malicious users intentionally disguise viruses and Trojans to trick users into running them. It is difficult for users to make safe choices about what software they should run.
With software restriction policies, you can protect your network from untrusted software by identifying and specifying the software that is allowed to run. You can define a default security level of Unrestricted or Disallowed for a Group Policy object (GPO) so that software is either allowed or not allowed to run by default. You can make exceptions to this default security level by creating software restriction policy rules for specific software. For example, if the default security level is set to Disallowed, you can create rules that allow specific software to run.

Security for Desktop Computers :

When a computer manufacturer delivers a new computer to an organization, the operating system is generally configured to provide the greatest flexibility to the typical user. Many organizations have additional software installed on top of the operating system, such as Microsoft Office. This provides power users with the tools they need to do their jobs.
However, many types of employees do not require much flexibility and will actually be more productive if the software on their computers is restricted. For example, a user in the accounts payable department might only need access to an e-mail client, accounting software, and a Web browser. For this type of user, restricting the applications they can run can make them more productive (for example, by removing Solitaire). Additionally, it can reduce the risk of malicious software, such as viruses and Trojans, infecting the computer.
In a typical restricted desktop computer role, the desktop and Start menu are significantly simplified. Users cannot make extensive customizations, other than a limited number of application-specific settings. Applications are typically allocated to users based on their job roles, and users cannot add or remove applications. This type of desktop configuration is appropriate in a marketing or finance department, for example.
In these areas, users require only a specific and limited set (typically three to five) of productivity and in-house applications to do their jobs.

Security for Mobile Computers :

Mobile computers require that you attend to several additional security considerations beyond those of desktop computers. Mobile users might use their computers while traveling, which might require them to perform administrative tasks that a member of the IT group would normally perform. For example, a mobile user might need to print a document using a different printer than the one installed in the office, and would need to install the correct printer driver. To allow this, disable the Devices: Prevent Users From Installing Printer Drivers security option. If you anticipate that users who work away from the office will need to install or reinstall applications while working remotely, you might want to enable the Always Install With Elevated Privileges setting in the Administrative Templates\Windows Components\Windows Installer node.
Mobile users might connect to foreign networks, such as a wireless hotspot at a coffee shop. These foreign networks won’t have the benefit of your organization’s network security, so mobile users have an elevated risk of being attacked across the network. To mitigate this risk, enable the Internet Connection Firewall (ICF, known in Service Pack 2 as Windows Firewall) on all network interfaces for mobile computers. Unfortunately, ICF cannot be configured by using Group Policy settings. Lesson 2 in this chapter contains more information about firewalls.

Lesson Summary

■ Software restriction policies can be applied to a GPO to restrict the applications that can run on a target system. Software restriction policies can restrict applications based on a hash of the executable file, the path in the file system, a certificate associated with the application, or the Internet zone from which the application is running.
■ You should create security templates for the various computer roles in your organizations, including desktop computers, mobile computers, and kiosks. Whenever possible, you should base these templates on a predefined security template.
■ Security templates are useful for creating GPOs, but they contain only a subset of the settings available when configuring a GPO. Therefore, after importing a security template into a GPO, you might have to use the Group Policy Object Editor to specify additional settings.
■ Mobile computers have different security considerations than desktop computers. Mobile computers are subject to a wider array of network attacks because they might connect to unprotected networks. Additionally, they are more likely to be stolen, so encryption of the disk’s physical contents might be necessary.
■ Kiosks require security settings that are tightly restricted to prevent abuse. GPOs allow an administrator to remove all major user interface elements and configure kiosk computers to log on a user and launch a single application automatically at startup.