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

If you can‘t send an email with iOS 11 and an Outlook.com or Exchange mail account

You might not be able to send email with an Outlook.com, Office 365, or Exchange account until you update to iOS 11.0.1.

If your email account is hosted by Microsoft on Outlook.com or Office 365, or an Exchange Server 2016 running on Windows Server 2016, you might see this error message when you try to send an email with iOS 11: “Cannot Send Mail. The message was rejected by the server.”

To fix the issue, update to iOS 11.0.1 or later.

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

Exchange Server 2016 online training courses now available

Microsoft announced the release of four new edX online training courses for Microsoft Exchange Server 2016. If you plan to implement Exchange Server 2016 or Exchange Online, or if you want to make sure that your implementation was done right, the Exchange Server 2016 online training courses are for you.

Course offerings include:

Each Exchange course is targeted to the IT professional audience, with hands-on labs that reinforce student learning. Students are graded on completing each module, as well as on module assessment exams and a final course exam. A Certificate can be earned by completing each course with a passing grade. Courses are self-paced, allowing IT professionals to build Exchange skills at their own pace as their schedules permit.

The first course, CLD208.1x: Microsoft Exchange Server 2016 Infrastructure, is free. The remaining three courses are for-fee courses at $49 USD per course.

edX is a massive open online course (MOOC) provider that was developed by MIT and Harvard University. The Microsoft Learning Experiences team has created a wide range of online training courses for edX, and these four Exchange courses are the team’s latest Office releases. They are the first of seven courses that cover the core skills an Exchange administrator needs to proficiently design, implement and manage an Exchange 2016 and Exchange Online implementation.

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