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Posts Tagged ‘Forefront’

Using PowerShell to Determine Forefront TMG Build Number

December 14, 2015 Comments off

Using PowerShell to Determine Forefront TMG Build NumberIdentifying the current build number of your Forefront TMG 2010 installation is critically important when making changes or updates to the system. It is generally recommended that all TMG firewalls be on the same release, so having this information is essential. Many TMG administrators use the TMG management console to gather this information, but I can tell you based on experience that this is not always the most accurate method to use.

I much prefer to gather this information programmatically at the command line. In the past I’ve written about using VBScript to do this, but it’s almost 2016 now and we really should be using PowerShell whenever possible. To that end, here are a few lines of PowerShell code you can use to accurately determine which version and build number your TMG firewall is currently running.

$FPC = New-Object -ComObject FPC.Root
$Server = $FPC.GetContainingServer()
$Server.ProductVersion

Using PowerShell to Determine Forefront TMG Build Number

If you’ve done any work at all with VBScript and the TMG’s FPC COM object, you’ll no doubt be able to convert some of your existing scripts to PowerShell. Also, PowerShell, with its tab auto completion, is much more discoverable than using VBScript with COM, so I’m sure you’ll be able to do a lot more with TMG using PowerShell.

Enjoy!

Reminder: Microsoft Reputation Services (MRS) End of Support

November 9, 2015 5 comments

Microsoft Reputation Services (MRS) End of SupportAs a reminder to anyone out there still using the URL filtering feature of their Forefront TMG 2010 firewall, the Microsoft Reputation Services (MRS) service, which provides URL categorization for TMG, will no longer be supported after December 31, 2015. After this date, Microsoft will cease updating their URL categorization database. In addition, there are no guarantees from Microsoft that the service will be available in any form, so customers still using this service are strongly encouraged to look for alternative solutions.

For many organizations, this means migrating to another platform entirely, which is not a bad idea considering that TMG is nearly six years old now. Alternatively, it is possible to replace TMG’s web filtering component. This can be done on premises by using integrations from various third-party vendors, or by using a cloud-based solution such as Zscaler.

Regardless which path you take, you have just over one month to identify and implement another URL filtering solution. Good luck!

Hotfix Rollup 2 for Forefront UAG 2010 Service Pack 4 Now Available

Hotfix Rollup 2 for Microsoft Forefront UAG 2010 Service Pack 4 is now available for download. This hotfix rollup includes fixes for the following issues:

KB3066351 – Client HTTP connections to a UAG redirect trunk receives errors after you install hotfix rollup 1 for Forefront UAG 2010 SP4

KB3070067 – You may receive an HTTP 503 “Service is Unavailable” error when a connection to a UAG trunk fails in Forefront UAG 2010 SP4

KB3068283 – You may receive HTTP 503 errors on a server that is running Forefront UAG 2010 SP4

KB3068289 – Moving mailboxes as part of a hybrid Office 365 migration fails in Forefront UAG 2010 SP4

You can download Hotfix Rollup 2 for Forefront UAG 2010 SP4 here.

Mitigating the POODLE SSL 3 Vulnerability on Forefront TMG 2010

October 21, 2014 20 comments

Recently a new and very serious vulnerability in the SSL 3.0 protocol has been discovered that allows an attacker to recover sensitive information for an encrypted session. The Qualys SSL Labs server test has been updated to identify and warn about this issue.

Mitigating the POODLE SSL 3.0 Vulnerability on Forefront TMG 2010

Figure 1 – Qualys SSL Labs Server Test Score for TMG Published Secure Web Site

On a Forefront TMG server with SSL hardening implemented as I’ve outlined here and here, the POODLE attack is mitigated, but it is still recommended that you disable SSL 3.0 altogether. SSL 3.0 is an old, outdated protocol that is no longer widely used, and disabling it should have minimal impact on clients connecting to secure web sites published by the Forefront TMG 2010 firewall.

To disable SSL 3.0 on the TMG firewall, open an elevated PowerShell window and execute the following commands:

New-Item -Path “HKLM:\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\SSL 3.0\Server” -Force

New-ItemProperty -Path “HKLM:\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\SSL 3.0\Server” -PropertyType dword -Value 0 -Name Enabled

Note: Use caution when copying/pasting the above commands as wrapping of the text has occurred.

A restart of the server is required for the change to take effect.

Forefront TMG 2010 Network Inspection System NIS Signature Updates

September 15, 2014 2 comments

When Microsoft announced the formal end-of-life for Forefront TMG 2010, they laid out in clear detail the support boundaries for the product going forward. Microsoft stated specifically that they would continue mainstream support for TMG until April of 2015, and extended support would terminate in April 2020. However, the Web Protection Service (WPS) updates for the URL filtering database, antimalware signatures, and the Network Inspection System (NIS) would only continue until December 31, 2015.

Unfortunately, it appears that Microsoft has abandoned the updating for NIS signatures. You may have noticed that a fully updated Forefront TMG firewall with the latest signature updates shows that the last NIS signature was released for security bulletin MS12-050 on July 20, 2012!

Forefront TMG 2010 Network Inspection System (NIS) Signature Updates

Forefront TMG 2010 Network Inspection System (NIS) Signature Updates

I find it difficult to believe that there hasn’t been a single vulnerability discovered or hotfix released since July of 2012 that wouldn’t benefit from NIS protection, so I have to assume that Microsoft is no longer supporting NIS in spite of their pledge to provide support for WPS through the end of 2015. If you are relying on NIS for essential network protection, it’s time to consider deploying a dedicated IDS/IPS solution or another solution that provides this functionality.

Recommended Forefront TMG 2010 SSL and TLS Configuration

September 8, 2014 6 comments

Last year I wrote an article for ISAserver.org that provided detailed guidance for improving security for SSL and TLS protected web sites using Forefront TMG 2010. Many people have reached out to me recently to ask about enabling forward secrecy, which my original article did not include because, at the time, it was not recommended to enable it. However, as times have changed, it is now recommended to enable forward secrecy so I recently wrote a short post with guidance on how to do that. The post was written with a very narrow scope and addressed only the enabling of forward secrecy for TLS. Many of you have since asked for guidance on overall security best practices with regard to SSL and TLS along with adding support for forward secrecy. In addition to the configuration changes detailed in my original ISAserver.org article, I also recommend the following list of SSL and TLS cipher suites be explicitly enforced using the method outlined here.

TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256_P256
TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256_P384
TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256_P521
TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384_P384
TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384_P521
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256_P256
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA_P256
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA_P256
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384_P256
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA_P256
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA_P256
TLS_DHE_DSS_WITH_AES_128_CBC_SHA256
TLS_DHE_DSS_WITH_AES_256_CBC_SHA256
TLS_DHE_DSS_WITH_AES_128_CBC_SHA
TLS_DHE_DSS_WITH_AES_256_CBC_SHA
TLS_RSA_WITH_AES_128_CBC_SHA256
TLS_RSA_WITH_AES_256_CBC_SHA256
TLS_RSA_WITH_AES_128_CBC_SHA
TLS_RSA_WITH_AES_256_CBC_SHA

Using this configuration, the Forefront TMG 2010 firewall should receive an A rating from the SSL Labs test site (at the time of this writing).

Forefront TMG 2010 SSL Security Configuration

Enabling and supporting the above list of cipher suites will provide the best overall protection and performance for your SSL protected web sites. Note that the list above does not include support for SSL 3.0. If you need to support SSL 3.0 you should add the following cipher suites to the end of the list.

TLS_RSA_WITH_RC4_128_SHA
TLS_RSA_WITH_RC4_128_MD5

Please note that this configuration may not work with older browsers on old, unsupported operating systems, for example Internet Explorer 6 on Windows XP. Before deploying this configuration in production I would encourage you to conduct some testing with your supported clients to ensure operability.

Enable TLS Forward Secrecy for Forefront TMG 2010 Published Web Sites

August 28, 2014 3 comments

Last year I wrote an article for ISAserver.org that outlined in detail how to improve SSL and TLS security for web sites published using Forefront TMG 2010. In its default configuration, Windows Server 2008 R2 and Forefront TMG leave quite a bit to be desired in terms of SSL and TLS security. In the article I demonstrated how to dramatically improve the security posture of TMG when publishing web sites that use SSL and TLS. At the time I wrote the article it was not recommended to enable forward secrecy, so the changes I originally proposed resulted in an “A” score from the Qualys SSL Labs test site. However, times have changed since then, and with the recent revelations of wide spread government spying, it is now recommended to enable forward secrecy by default. Sites that don’t support forward secrecy will now receive a reduced grade.

Enable TLS Forward Secrecy for Forefront TMG 2010 Published Web Sites

To accomplish this on the Forefront TMG 2010 firewall, open the Local Group Policy Editor (gpedit.msc) and navigate to Computer Configuration, Administrative Templates, Network, SSL Configuration Settings. Double-click SSL Cipher Suite Order and choose Enabled. Copy the list of SSL cipher suites to a blank notepad document and then move all of the cipher suites that begin with TLS_ECDHE_RSA_WITH_AES_ to the front of the list. Use caution here because the list cannot have any extra commas, line breaks, or spaces at all. Paste the updated list back in to the SSL Cipher Suites box and click Ok.

Enable TLS Forward Secrecy for Forefront TMG 2010 Published Web Sites

The server will have to be restarted for the changes to take effect. Once complete, forward secrecy will now be used by modern browsers and you should once again receive an “A” grade from SSL Labs.

Enable TLS Forward Secrecy for Forefront TMG 2010 Published Web Sites