Microsoft Exchange Memory Corruption Vulnerability

A remote code execution vulnerability exists in Microsoft Exchange software when the software fails to properly handle objects in memory. An attacker who successfully exploited the vulnerability could run arbitrary code in the context of the System user. An attacker could then install programs; view, change, or delete data; or create new accounts.

Exploitation of the vulnerability requires that a specially crafted email be sent to a vulnerable Exchange server.

The security update addresses the vulnerability by correcting how Microsoft Exchange handles objects in memory.

Download:

Product Link
Microsoft Exchange Server 2010 Service Pack 3 Update Rollup 21

4091243

Microsoft Exchange Server 2013 Cumulative Update 19

4092041

Microsoft Exchange Server 2013 Cumulative Update 20

4092041

Microsoft Exchange Server 2013 Service Pack 1

4092041

Microsoft Exchange Server 2016 Cumulative Update 8

4092041

Microsoft Exchange Server 2016 Cumulative Update 9

4092041

Exchange 2016 Cumulative Update 9 and Exchange 2013 Cumulative Update 20

On March 20, 2018 Microsoft has released two new quarterly updates:

  • Exchange 2016 Cumulative Update 9 (CU9)
  • Exchange 2013 Cumulative Update 20 (CU20)
TLS 1.2

There aren’t too many new features in these CUs. The most important ‘feature’ is that TLS 1.2 is now fully supported (most likely you already have TLS 1.2 only on your load balancer). This is extremely supported since Microsoft will support TLS 1.2 ONLY in Office 365 in the last quarter of this year (see the An Update on Office 365 Requiring TLS 1.2 Microsoft blog as well).

Dot.net Support

Support for .NET Framework 4.7.1, or the ongoing story about the .NET Framework. The .NET Framework 4.7.1 is fully supported by Exchange 2016 CU9 and Exchange 2013 CU20. Why is this important? For the upcoming CUs in three months (somewhere in June 2018) the .NET Framework 4.7.1 is mandatory, so you need these to be installed in order to install these upcoming CUs.

Please note that .NET Framework 4.7 is NOT supported!

If you are currently running an older CU of Exchange, for example Exchange 2013 CU12, you have to make an intermediate upgrade to Exchange 2013 CU15. Then upgrade to .NET Framework 4.6.2 and then upgrade to Exchange 2013 CU20. If you are running Exchange 2016 CU3 or CU4, you can upgrade to .NET Framework 4.6.2 and then upgrade to Exchange 2016 CU9.

Schema changes

If you are coming from a recent Exchange 2013 CU, there are no schema changes since the schema version (rangeUpper = 15312) hasn’t changed since Exchange 2013 CU7. However, since there can be changes in (for example) RBAC, it’s always a good practice to run the Setup.exe /PrepareAD command. For Exchange 2016, the schema version (rangeUpper = 15332) hasn’t changed since Exchange 2016 CU7.

As always, check the new CUs in your lab environment before installing into your production environment!!

Exchange 2016 CU9 Information and download Links
Exchange 2013 CU20 Information and download Links

Exchange Server 2013 enters the Extended Support phase of product lifecycle on April 10th, 2018. During Extended Support, products receive only updates defined as Critical consistent with the Security Update Guide. For Exchange Server 2013, critical updates will include any required product updates due to time zone definition changes.

Exchange 2013 CU19

Exchange 2013 CU19 fixes:

  • 4046316 MAPI over HTTP can’t remove client sessions timely if using OAuth and the resource has a master account in Exchange Server 2013
  • 4046205 W3wp high CPU usage in Exchange Server 2013
  • 4046182 Event ID 4999 or 1007 if diagnostics service crashes repeatedly in Exchange Server 2013
  • 4056329 Can’t access EWS from Outlook/OWA add-ins via makeEwsRequestAsync in Exchange Server 2016 and Exchange Server 2013
  • 4045655 Description of the security update for Microsoft Exchange: December 12, 2017

Version

Build

KB Article

Download

UMLP

Schema Changes

Exchange 2013 CU19

15.0.1365.1

KB4037224

Download

UMLP

No

Exchange 2016 CU8 15.1.1415.2 KB4035145

Exchange 2016 CU8 fixes:

  • 4056329 Can’t access EWS from Outlook/OWA add-ins via makeEwsRequestAsync in Exchange Server 2016 and Exchange Server 2013
  • 4054516 “Your request can’t” error when accessing an archive mailbox via OWA in Exchange Server 2016
  • 4055953 The recipient scope setting doesn’t work for sibling domains in Exchange Server 2016
  • 4055435 No MAPI network interface is found after you install Exchange Server 2016 CU7
  • 4056609 Event ID 4999 and mailbox transport delivery service does not start after you install Exchange Server 2016 CU7
  • 4045655 Description of the security update for Microsoft Exchange: December 12, 2017
  • 4057248 Many Watson reports for StoragePermanentException in Exchange Server 2016

Version

Build

KB Article

Download

UMLP

Schema Changes

Exchange 2016 CU8

15.1.1415.2

KB4035145

Download

UMLP

Yes

Exchange Server 2016 Cumulative Update 7 (KB4018115) and Exchange Server 2013 Cumulative Update 18 (KB4022631)

The latest set of Cumulative Updates for Exchange Server 2016 and Exchange Server 2013 are now available on the download center.  These releases include fixes to customer reported issues, all previously reported security/quality issues and updated functionality.

Minimum supported Forest Functional Level is now 2008R2

In our blog post, Active Directory Forest Functional Levels for Exchange Server 2016, we informed customers that Exchange Server 2016 would enforce a minimum 2008R2 Forest Functional Level requirement for Active Directory.  Cumulative Update 7 for Exchange Server 2016 will now enforce this requirement.  This change will require all domain controllers in a forest where Exchange is installed to be running Windows Server 2008R2 or higher.  Active Directory support for Exchange Server 2013 remains unchanged at this time.

Support for latest .NET Framework

The .NET team is preparing to release a new update to the framework, .NET Framework 4.7.1.  The Exchange Team will include support for .NET Framework 4.7.1 in our December Quarterly updates for Exchange Server 2013 and 2016, at which point it will be optional.  .NET Framework 4.7.1 will be required on Exchange Server 2013 and 2016 installations starting with our June 2018 quarterly releases.  Customers should plan to upgrade to .NET Framework 4.7.1 between the December 2017 and June 2018 quarterly releases.

The Exchange team has decided to skip supporting .NET 4.7.0 with Exchange Server.  We have done this not because of problems with the 4.7.0 version of the Framework, rather as an optimization to encourage adoption of the latest version.

Known unresolved issues in these releases

The following known issues exist in these releases and will be resolved in a future update:

  • Online Archive Folders created in O365 will not appear in the Outlook on the Web UI
  • Information protected e-Mails may show hyperlinks which are not fully translated to a supported, local language

Release Details

KB articles that describe the fixes in each release are available as follows:

Exchange Server 2016 Cumulative Update 7 does not include new updates to Active Directory Schema.  If upgrading from an older Exchange version or installing a new server, Active Directory updates may still be required.  These updates will apply automatically during setup if the logged on user has the required permissions.  If the Exchange Administrator lacks permissions to update Active Directory Schema, a Schema Admin must execute SETUP /PrepareSchema prior to the first Exchange Server installation or upgrade.  The Exchange Administrator should execute SETUP /PrepareAD to ensure RBAC roles are current.

Exchange Server 2013 Cumulative Update 18 does not include updates to Active Directory, but may add additional RBAC definitions to your existing configuration. PrepareAD should be executed prior to upgrading any servers to Cumulative Update 18. PrepareAD will run automatically during the first server upgrade if Exchange Setup detects this is required and the logged on user has sufficient permission.

Additional Information

Microsoft recommends all customers test the deployment of any update in their lab environment to determine the proper installation process for your production environment. For information on extending the schema and configuring Active Directory, please review the appropriate TechNet documentation.

Also, to prevent installation issues you should ensure that the Windows PowerShell Script Execution Policy is set to “Unrestricted” on the server being upgraded or installed. To verify the policy settings, run the Get-ExecutionPolicy cmdlet from PowerShell on the machine being upgraded. If the policies are NOT set to Unrestricted you should use the resolution steps in KB981474 to adjust the settings.

Reminder: Customers in hybrid deployments where Exchange is deployed on-premises and in the cloud, or who are using Exchange Online Archiving (EOA) with their on-premises Exchange deployment are required to deploy the most current (e.g., 2013 CU18, 2016 CU7) or the prior (e.g., 2013 CU17, 2016 CU6) Cumulative Update release.

For the latest information on Exchange Server and product announcements please see What’s New in Exchange Server 2016 and Exchange Server 2016 Release Notes.  You can also find updated information on Exchange Server 2013 in What’s New in Exchange Server 2013, Release Notes and product documentation available on TechNet.

Note: Documentation may not be fully available at the time this post is published.

Exchange 2010-2016 Security Fixes

Microsoft released security updates to fix a remote code execution vulnerability in
Exchange Server. The related knowledge base article is KB4018588.

More information is contained in the following Common Vulnerabilities and Exposures articles:

  • CVE-2017-8521 – Scripting Engine Memory Corruption Vulnerability
  • CVE-2017-8559 – Microsoft Exchange Cross-Site Scripting Vulnerability
  • CVE-2017-8560 – Microsoft Exchange Cross-Site Scripting Vulnerability

Depending on the lifecycle status of the product, fixes are made available either through a Rollup or as a security fix for the following product levels:

As you might notice, the security fix is made available for the N-1 builds of Exchange 2013 and Exchange 2016. This could imply the issue was addressed in the latest builds of those products. I hope to receive official confirmation on this soon.

The issue is deemed Important, which means organizations are advised to apply these updates at the earliest opportunity. However, as with any update, it is recommended to thoroughly test updates and fixes prior to deploying them in a production environment.

Source

CPU usage is high when you use RPC over HTTP protocol in Windows 8.1 or Windows Server 2012 R2

Consider the following scenario that takes Microsoft Exchange Server 2013 as an example:

  • The Mailbox server role is enabled in Exchange Server 2013.
  • Exchange mailboxes use extended MAPI to communicate with the Exchange Server.
  • The extended MAPI uses Microsoft RPC over HTTP (remote procedure call over HTTP) protocol.
  • Many clients (such as mobile devices) are dropping connections to the Exchange Server.

In this scenario, the CPU usage on the Exchange server may reach 100 percent.\

Hotfix: https://support.microsoft.com/en-us/hotfix/kbhotfix?kbnum=3041832&kbln=en-US

EXCHANGE 2013 CU17 AND EXCHANGE 2016 CU6

On June 27, 2017 Microsoft has released its quarterly updates for Exchange 2013 and Exchange 2016. The current version is now at Exchange 2013 CU17 (15.0.1320.4) and Exchange 2016 CU6(15.1.1034.26) . But this time there are some interesting things I’d like to point out.

A couple of days before the release of Exchange 2016 CU6 (15.1.1034.26)
Microsoft blogged about Sent Items Behavior Control and Original Folder Item Recovery. With the Sent Items Behavior Control, a message that’s sent using the Send As or Send on behalf of permission is not only stored in the mailbox of the user that actually sent the message, but a copy is also stored in the delegator mailbox sent items. This was already possible for shared mailboxes, but now it’s also possible for regular mailboxes (like manager/assistant scenarios).

The Original Folder Item Recovery feature is I guess on of the most requested features. In the past (before Exchange 2010) when items were restored after they were deleted, they were restored to their original location. With the Dumpster 2.0 that was introduced with Exchange 2010 this was no longer possible, and items were restored to the deleted items folder. In this case the items had to be moved manually to their original location. With the introduction of the Original Folder Item Recovery the restore of deleted items again takes place in the original folder.

Unfortunately, both Sent Items Behavior Control and Original Folder Item Recovery are only available in Exchange 2016 CU6 (and NOT in Exchange 2013 CU17).

When it comes to security TLS 1.2 is a hot topic. Microsoft is aware of this and working hard towards an Exchange environment that only uses TLS 1.2 (so that TLS 1.1 and TLS 1.0 can be disabled). We are not yet at that stage. Exchange 2016 CU6 does have improved support for TLS 1.2, but Microsoft is not encouraging customers to move to a TLS 1.2 environment only.

.NET Framework and Exchange server continues to be a difficult scenario. This is understandable, Exchange is just a consumer of Windows and .NET so the Exchange Product Group does not have much influence on the .NET (and Windows) Product Group.

Exchange 2016 CU6 does NOT support.NET Framework 4.7 at this moment, and you should NOT install .NET Framework on a server running Exchange 2016. Not before and not after the installation of Exchange 2016 CU6. This is also true for Exchange Server 2013 CU17. More information regarding .NET Framework and Exchange server can be found here: https://blogs.technet.microsoft.com/exchange/2017/06/13/net-framework-4-7-and-exchange-server/.

The .NET Framework 4.6.2 is supported by Exchange 2016 CU3 and higher and Exchange 2013 CU15 and higher. For a complete overview of which scenarios are supported, navigate to the Exchange Server Supportability Matrix on https://technet.microsoft.com/en-us/library/ff728623(v=exchg.150).aspx.

KB articles that describe the fixes, features and information in each release are available as follows:

Version

Build

KB Article

Download

UMLP

Schema Changes

Exchange 2016 CU6

15.1.1034.26

KB4012108

Download

UMLP

Yes

Exchange 2013 CU17

15.0.1320.4

KB4012114

Download

UMLP

No

Source: jaapwesselius

Exchange 2016/2013/2010 Updates March 2017

Today, the Exchange Team released the March updates for Exchange Server 2013 and 2016, as well as Exchange Server 2010 and 2007. The latter will receive its last update, as Exchange 2007 will reach end-of-life April 11, 2017.

As announced in December updates, Exchange 2013 CU16 and Exchange 2016 CU5 require .NET 4.6.2. The recommended upgrade paths:

  • If you are still on .NET 4.6.1, you can upgrade to .NET 4.6.2 prior of after installing the latest Cumulative Update.
  • If you are on .NET 4.52, upgrade to Exchange 2016 CU4 or Exchange 2013 CU15 if you are not already on that level, then upgrade to .NET 4.6.2, and finally upgrade to the the latest Cumulative Update.

The Cumulative Updates also include DST changes, which is also contained in the latest Rollups published for Exchange 2010 and 2007.

For a list of fixes in these updates, see below.

Exchange 2016 CU5

15.1.845.34

KB4012106

Download

UMLP

Exchange 2013 CU16

15.0.1293.2

KB4012112

Download

UMLP

Exchange 2010 SP3 Rollup 17

14.3.352.0

KB4011326

Download

 

Exchange 2007 SP3 Rollup 23

8.3.517.0

KB4011325

Download

 

Exchange 2016 CU5 fixes:

  • KB4015665 SyncDelivery logging folders and files are created in wrong location in Exchange Server 2016
  • KB4015664 A category name that has different case-sensitivity than an existing name is not created in Exchange Server 2016
  • KB4015663 “The message content has become corrupted” exception when email contains a UUE-encoded attachment in Exchange Server 2016
  • KB4015662 Deleted inline picture is displayed as attachment after you switch the message to plain text in Exchange Server 2016
  • KB4015213 Email is still sent to Inbox when the sender is deleted from the Trusted Contacts list in Exchange Server 2016
  • KB4013606 Search fails on Exchange Server 2016 or Exchange Server 2013
  • KB4012994 PostalAddressIndex element isn’t returning the correct value in Exchange Server 2016

Exchange 2013 CU16 fixes:

  • KB4013606 Search fails on Exchange Server 2016 or Exchange Server 2013

Notes:

Exchange 2016 CU5 doesn’t include schema changes, however, Exchange 2016 CU5 as well as Exchange 2013 CU16 may introduce RBAC changes in your environment. Where applicable, use setup /PrepareSchema to update the schema or /PrepareAD to apply RBAC changes, before deploying or updating Exchange servers. To verify this step has been performed, consult the Exchange schema overview.

When upgrading your Exchange 2013 or 2016 installation, don’t forget to put the server in maintenance mode when required. Do note that upgrading, before installing the Exchange binaries, setup will put the server in server-wide offline-mode.

Using Windows Management Framework (WMF)/PowerShell version 5 on anything earlier than Windows Server 2016 is not supported. Don’t install WMF5 on your Exchange servers running on Windows Server 2012 R2 or earlier.

When using Exchange hybrid deployments or Exchange Online Archiving (EOA), you are allowed to stay at least one version behind (n-1).

  • If you want to speed up the update process for systems without internet access, you can follow the procedure described here to disable publisher’s certificate revocation checking.
  • Cumulative Updates can be installed directly, i.e. no need to install RTM prior to installing Cumulative Updates.
  • Once installed, you can’t uninstall a Cumulative Update nor any of the installed Exchange server roles.
  • The order of upgrading servers with Cumulative Updates is irrelevant.

Caution: As for any update, I recommend to thoroughly test updates in a test environment prior to implementing them in production. When you lack such facilities, hold out a few days and monitor the comments on the original publication or forums for any issues.

Source

Exchange Team has released Quarterly Exchange Updates

– A new Outlook on the web compose experience
– Support for .Net 4.6.2
– Change to Pre-Requisites installed by Setup
– Update on Windows Server 2016 support KB3206632
– Latest time zone updates
– Important Public Folder fix included in these releases

Exchange Server 2016 Cumulative Update 4 (KB3177106), Download, UM Lang Packs
Exchange Server 2013 Cumulative Update 15 (KB3197044), Download, UM Lang Packs
Exchange Server 2010 Service Pack 3 Update Rollup 16 (KB3184730), Download
Exchange Server 2007 Service Pack 3 Update Rollup 22 (KB3184712), Download

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