Security Updates Exchange 2013-2019 (Mar2022)


The Exchange PG released March updates for Exchange Server 2013, 2016 and 2019. More detailed information on patching and how to get current when running an earlier CU of Exchange, can be found at the original blog post here.

The vulnerabilities addressed in these security updates are:

VulnerabilityCategorySeverityRating
CVE-2022-23277Remote Code ExecutionCriticalCVSS:3.1 8.8 / 7.7
CVE-2022-24463SpoofingImportantCVSS:3.1 6.5 / 5.7

These vulnerabilities are addressed in the following security updates below. The exception is KB5010324 which does not fix CVE-2022-24463 for Exchange 2013. If this is because of the severity classification or the problem being non-existent for Exchange 2013, has not been not disclosed.

ExchangeDownloadBuildKBSupersedes
Exchange 2019 CU11Download15.2.986.22KB5012698KB5008631
Exchange 2019 CU10Download15.2.922.27KB5012698KB5008631
Exchange 2016 CU22Download15.1.2375.24KB5012698KB5008631
Exchange 2016 CU21Download15.1.2308.27KB5012698KB5008631
Exchange 2013 CU23Download15.0.1497.33KB5010324KB5008631

Finally, KB5010324 also contains the following additional fix for Exchange 2013:

  • 5012925 RFC certificate timestamp validation in Exchange Server 2013

Be advised that these security updates are Cumulative Update level specific. You cannot apply the update for Exchange 2019 CU11 to Exchange 2019 CU10. Also, the security update download has the same name for different Cumulative Updates, and I would suggest tagging the file name with the CU level, e.g. Exchange2019-CU10-KBXXXXXX-x64-en.msp.

As a reminder, run the Security Update from an elevated command prompt to prevent issues during installation. In other words: Do not just double-click on the .MSP file. And on a final note, as with any patch or update, I’d recommend to apply this in a test environment first, prior to implementing it in production. However, it is not recommended to wait for regular maintenance cycles when it concerns security updates, and follow a more agile approach; the ratings are an indication of the urgency.

Security Updates Exchange 2013-2019 (Jan2022)


Another year, another Patch Tuesday! A quick blog on January 2022’s security updates for Exchange Server 2013 up to 2019.

The vulnerabilities addressed in these security updates are:

VulnerabilityCategorySeverityRating
CVE-2022-21969Remote Code ExecutionImportantCVSS:3.1 9.0 / 7.8
CVE-2022-21855Remote Code ExecutionImportantCVSS:3.1 9.0 / 7.8
CVE-2022-21846Remote Code ExecutionCriticalCVSS:3.0 9.0 / 7.8

Vulnerabilities mentioned in the table above are addressed in the following security updates.

ExchangeDownloadBuildKBSupersedes
Exchange 2019 CU11Download15.2.986.15KB5008631KB5007409
Exchange 2019 CU10Download15.2.922.20KB5008631KB5007409
Exchange 2016 CU22Download15.1.2375.18KB5008631KB5007409
Exchange 2016 CU21Download15.1.2308.21KB5008631KB5007409
Exchange 2013 CU23Download15.0.1497.28KB5008631KB5007409

More detailed information can be found at the original blog post here. The security update also fixes the OWA redirection problem for Exchange hybrid deployments introduced with the November security updates.

Be advised that these security updates are Cumulative Update level specific. You cannot apply the update for Exchange 2019 CU11 to Exchange 2019 CU10. Also, the security update download has the same name for different Cumulative Updates, and I would suggest tagging the file name with the CU level, e.g. Exchange2019-CU10-KBXXXXXX-x64-en.msp.

As a reminder, run the Security Update from an elevated command prompt to prevent issues during installation. In other words: Do not just double-click on the .MSP file. And on a final note, as with any patch or update, I’d recommend to apply this in a test environment first, prior to implementing it in production. However, it is not recommended to wait for regular maintenance cycles when it concerns security updates, and follow a more agile approach; the ratings are an indication of the urgency.

Security Updates Exchange 2013-2019 (Nov2021)


Another month, another Patch Tuesday! A quick blog on November’s security updates for Exchange Server 2013 up to 2019. The vulnerabilities addressed in these security updates are:

VulnerabilityCategorySeverityRating
CVE-2021-42321Remote Code ExecutionImportantCVSS:3.1 8.8 / 7.7
CVE-2021-42305SpoofingImportantCVSS:3.1 6.5 / 5.7
CVE-2021-41349SpoofingImportantCVSS:3.1 6.5 / 5.7

Vulnerabilities mentioned in the table above are addressed in the following security updates. Exception is Exchange 2013 CU23 which seemingly only gets fixed for CVE-2021-26427; it is unclear if that is because of Exchange 2013’s lifecycle phase or because the problem does not exist in those builds.

ExchangeDownloadBuildKBSupersedes
Exchange 2019 CU11Download15.2.986.14KB5007409KB5007012, KB5007011
Exchange 2019 CU10Download15.2.922.19KB5007409KB5007012, KB5007011
Exchange 2016 CU22Download15.1.2375.17KB5007409KB5007012, KB5007011
Exchange 2016 CU21Download15.1.2308.20KB5007409KB5007012, KB5007011
Exchange 2013 CU23Download15.0.1497.26KB5007409KB5007012, KB5007011

More detailed information can be found at the original blog post here. Check the KB articles for any known release notes, such as the possible cross-forest Free/Busy issue and HTTP headers containing version information.

Be advised that these security updates are Cumulative Update level specific. You cannot apply the update for Exchange 2019 CU11 to Exchange 2019 CU10. Also, the security update download has the same name for different Cumulative Updates, and I would suggest tagging the file name with the CU level, e.g. Exchange2019-CU10-KBXXXXXX-x64-en.msp.

As a reminder, run the Security Update from an elevated command prompt to prevent issues during installation. In other words: Do not just double-click on the .MSP file. And on a final note, as with any patch or update, I’d recommend to apply this in a test environment first, prior to implementing it in production. However, it is not recommended to wait for regular maintenance cycles when it concerns security updates, and follow a more agile approach; the ratings are an indication of the urgency.

Security Updates Exchange 2013-2019 (Oct2021)


Welcome to another Patch Tuesday! A quick blog on October’s security updates for Exchange Server 2013 up to 2019.

The vulnerabilities addressed in these security updates are:

VulnerabilityCategorySeverityRating
CVE-2021-26427Remote Code ExecutionImportantCVSS:3.0 9.0 / 7.8
CVE-2021-41350SpoofingImportantCVSS:3.0 6.5 / 5.7
CVE-2021-41348Elevation of PrivilegeImportantCVSS:3.0 8.0 / 7.0
CVE-2021-34453Denial of ServiceImportantCVSS:3.0 7.5 / 6.5

Vulnerabilities mentioned in the table above are addressed in the following security updates. Exception is Exchange 2013 CU23 which seemingly only gets fixed for CVE-2021-26427; it is unclear if that is because of Exchange 2013’s lifecycle phase or because the problem does not exist in those builds.

ExchangeDownloadBuildKBSupersedes
Exchange 2019 CU11Download15.2.986.9KB5007012
Exchange 2019 CU10Download15.2.922.14KB5007012
Exchange 2016 CU22Download15.1.2375.12KB5007012
Exchange 2016 CU21Download15.1.2308.15KB5007012
Exchange 2013 CU23Download15.0.1497.24KB5007011

More detailed information can be found at the original blog post here. Check the KB articles for any known release notes, such as the possible cross-forest Free/Busy issue and HTTP headers containing version information.

Be advised that these security updates are Cumulative Update level specific. You cannot apply the update for Exchange 2019 CU11 to Exchange 2019 CU10. Also, the security update download has the same name for different Cumulative Updates, and I would suggest tagging the file name with the CU level, e.g. Exchange2019-CU10-KBXXXXXX-x64-en.msp.

As a reminder, run the Security Update from an elevated command prompt to prevent issues during installation. In other words: Do not just double-click on the .MSP file. And on a final note, as with any patch or update, I’d recommend to apply this in a test environment first, prior to implementing it in production. However, it is not recommended to wait for regular maintenance cycles when it concerns security updates, and follow a more agile approach; the ratings are an indication of the urgency.

Exchange Updates – September 2021


The Exchange Team released the quarterly Cumulative Updates for Exchange Server 2019 as well as Exchange 2016.

Be advised that these CUs will introduce something which is called the Exchange Emergency Mitigation Service. This service is designed to distribute and implement mitigations addressing potential threats. For this, the URL Rewrite Module needs to be installed on the Exchange server. When you have Exchange running on Windows Server 2012 R2, you will also need an update for the Universal C Runtime (KB2999226). Periodically, the EEM service will reach out to the Office Config Service (OCS) through endpoint https://officeclient.microsoft.com, and update its set of configured mitigations. More on EEM and managing its configuration here.

Links to the updates as well as a description of changes and fixes are described below. The column Schema and AD indicate if the CU contains Schema (/PrepareSchema) and Active Directory (PrepareAD) changes compared to the previous CU. Refer to the Exchange Schema page for schema and related versioning information.

VersionBuildKBDownloadUMLPSchemaAD
Exchange 2019 CU1115.2.986.5KB5005334Download NY
Exchange 2016 CU2215.1.2375.7KB5005333DownloadUMLPNY

Exchange 2019 CU11 fixes:

  • 5006980 Bad signature error using PerfView in Exchange Server 2019 and 2016 (KB5006980)
  • 5006982 On-premises Exchange queues back up because of incorrect default value (KB5006982)
  • 5006983 Exchange Server 2019 and 2016 certificates created during setup use SHA-1 hash (KB5006983)
  • 5006984 PrepareAD fails if Computers container or RODCs are renamed or moved in Exchange Server 2019 and 2016 (KB5006984)
  • 5006986 Opening an Outlook message from the desktop removes line spacing (KB5006986)
  • 5006988 Export of .pst file is unexpectedly triggered again in Exchange Server 2019 and 2016 (KB5006988)
  • 5006989 Accepted domains with wildcards for subdomains are not honored when Edge server maps AddressSpaces (KB5006989)
  • 5006990 Exchange CU installation fails after you configure fallback to use default character set (5006990)
  • 5006991 Mail quota warning messages no longer sent daily in Exchange Server 2019 (KB5006991)
  • 5006992 No room lists found when trying to add a room in OWA in Exchange Server 2019 or 2016 (KB5006992)
  • 5006993 Can’t log on to OWA in Chrome if SSL is offloaded in Exchange Server 2019 and 2016 (KB5006993)
  • 5006994 BCC values not retained in Sent Items in a shared mailbox in Exchange Server 2019 and 2016 (5006994)
  • 5006995 Korean email messages display some recipients incorrectly in Exchange Server 2019 and 2016 (KB5006995)
  • 5006996 Export-AutoDiscoverConfig exposes admin password and does not work against domain controllers that require signing (KB5006997)
  • 5006997 Korean messages in OWA display “From” as “Start date” after you filter the list in Exchange Server 2019 and 2016
  • 5006999 “401” error and Outlook repeatedly prompts for credentials in Exchange Server 2019 (KB5006999)
  • 5007042 Error window appears when you view features in OWA Virtual Directory (KB5007042)
  • 5007043 Exchange Server SU updates Add/Remove Programs incorrectly (KB5007043)
  • 5007044 Start-MailboxAssistant not available in EMS in Exchange Server 2019 (KB5007044)

Exchange 2016 CU22 fixes:

  • 5006980 Bad signature error using PerfView in Exchange Server 2019 and 2016 (KB5006980)
  • 5006982 On-premises Exchange queues back up because of incorrect default value (KB5006982)
  • 5006983 Exchange Server 2019 and 2016 certificates created during setup use SHA-1 hash (KB5006983)
  • 5006984 PrepareAD fails if Computers container or RODCs are renamed or moved in Exchange Server 2019 and 2016 (KB5006984)
  • 5006986 Opening an Outlook message from the desktop removes line spacing (KB5006986)
  • 5006988 Export of .pst file is unexpectedly triggered again in Exchange Server 2019 and 2016 (KB5006988)
  • 5006989 Accepted domains with wildcards for subdomains are not honored when Edge server maps AddressSpaces (KB5006989)
  • 5006992 No room lists found when trying to add a room in OWA in Exchange Server 2019 or 2016 (KB5006992)
  • 5006993 Can’t log on to OWA in Chrome if SSL is offloaded in Exchange Server 2019 and 2016 (KB5006993)
  • 5006994 BCC values not retained in Sent Items in a shared mailbox in Exchange Server 2019 and 2016 (5006994)
  • 5006995 Korean email messages display some recipients incorrectly in Exchange Server 2019 and 2016 (KB5006995)
  • 5006996 Export-AutoDiscoverConfig exposes admin password and does not work against domain controllers that require signing (KB5006997)
  • 5006997 Korean messages in OWA display “From” as “Start date” after you filter the list in Exchange Server 2019 and 2016
  • 5007042 Error window appears when you view features in OWA Virtual Directory (KB5007042)
  • 5007043 Exchange Server SU updates Add/Remove Programs incorrectly (KB5007043)

Notes:

  • If these Cumulative Updates contain schema changes compared to the Cumulative Update you have deployed, you need to run Setup with /PrepareSchema. If they contain Active Directory changes, you need to run /PrepareAD. Alternatively, permissions permitting, you can let Setup perform this step. Consult the Exchange schema versions page for schema and related versioning information.
  • When upgrading from an n-2 or earlier version of Exchange, or an early version of the .NET Framework, consult Upgrade Paths for CU’s & .NET.
  • Don’t forget to put the Exchange server in maintenance mode prior to updating. Regardless, setup will put the server in server-wide offline mode post-analysis, before making actual changes.
  • When using Exchange hybrid deployments or Exchange Online Archiving (EOA), support requires you to trail at most one version (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; no need to install RTM prior to installing Cumulative Updates.
  • Once upgraded, you can’t uninstall a Cumulative Update nor any of the installed Exchange server roles.
  • The recommended upgrade order is internet-facing, non-internet-facing servers first, followed by Edge Transports.

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.

Exchange Updates – October 2018


Ex2013 LogoThe Exchange Team released the October update for Exchange Server 2016. You may notice the absence of Exchange 2013, which is now in extended support phase and thus won’t receive regular updates. This heads-up was also given together with the updates of June.

Version Build KB Download UMLP Schema?
Exchange 2016 CU11 15.1.1591.10 KB4134118 Download UMLP No

This update contain the following important changes and notes:

  • Exchange 2016 CU11 – as well as Exchange 2013 CU21 – are supported with .NET Framework 4.7.2; at least .NET Framework 4.7.1 is required for both.
  • Exchange 2016 CU13 (the June 2019 release, December will be skipped) will start requiring .NET Framework 4.7.2, similar to the release of Exchange 2019; Windows Server 2019 will contain .NET Framework 4.7.2.
  • Exchange 2016 requires installation of VC++ 2012 runtime prior to installation. Additionally, when installing the Mailbox role, VC++ 2013 runtime needs to be installed as well.

Exchange 2016 CU11 fixes:

  • 4076516 Email message body is garbled when the Russian version of Outlook is used in Exchange Server 2016
  • 4095967 CultureNotFoundException when you select an LCID 4096 language in Exchange Server 2016
  • 4456225 The image in a signature that’s created in Outlook on the web isn’t visible to external users in Exchange Server 2016
  • 4456226 Require SSL setting of MAPI virtual directory is reset after you install a cumulative update of Exchange Server 2016
  • 4456227 ActiveSync clients cannot connect or synchronizing is delayed in an Exchange Server environment
  • 4456228 Add an option to control UseAscReqNoToken through app configuration for Exchange Server 2016
  • 4456229 Irrelevant management role entries without parameters are displayed in Exchange Server 2016
  • 4456230 Component/protocol level bypass option for InternetWebProxy to avoid unnecessary proxy traffic within internal networks
  • 4456231 AdvancedDataGovernanceLogs is created on the D drive after deploying Exchange Server 2016
  • 4456232 Outlook on the web enters an authentication loop when you use device registration in Exchange Server 2016
  • 4456234 Email can’t be delivered when the subject has an unknown character set in Exchange Server 2016
  • 4456240 “CrimsonProbe has been poisoned repeatedly” error when migrating mailboxes to Exchange Server 2016
  • 4456243 Hashed lines shown in scheduling assistant when Exchange Server 2016 tries to retrieve free/busy information across untrusted forests
  • 4456244 Public folder forwards the new item that you create in Exchange Server 2016
  • 4456245 Event ID 4999 and NullReferenceException when the New-MailboxRestoreRequest and New-MailboxExportRequest cmdlets fail in Exchange Server 2016
  • 4456247 StoreDriver.config validation fails then meeting reminder can’t be set to “None” in Exchange Server 2016
  • 4456249 Message tracking logs can’t be fully indexed in Exchange Server 2016
  • 4456250 Users can download and view attachments that exceed the maximum attachment size setting in mobile device mailbox policy in Exchange Server 2016
  • 4456259 Exchange Server 2016 user can’t access a shared calendar from Exchange Server 2013
  • 4456233 UAPStatisticsLog and RecordReview are created on the D drive after you deploy Exchange Server 2016
  • 4459847 Can’t send S/MIME encrypted mail or update the S/MIME control from Outlook on the web in Exchange Server 2016

Notes:

  • Exchange 2016 CU11 does not contain schema changes compared to their previous Cumulative Update. However, they may introduce RBAC changes in your environment. Use setup /PrepareAD to apply RBAC changes, before deploying or updating Exchange servers.
  • When upgrading from an n-2 or earlier version of Exchange, or an early version of the .NET Framework, consult Upgrade Paths for CU’s & .NET.
  • Don’t forget to put the Exchange server in maintenance mode prior to updating. Regardless, setup will put the server in server-wide offline mode post-analysis, before making actual changes.
  • When using Exchange hybrid deployments or Exchange Online Archiving (EOA), you are required to stay at most 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; 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 in which you upgrade 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.

Exchange 2013 Cumulative Update 11


Ex2013 LogoThe Exchange Team released Cumulative Update 11 for Exchange Server 2013 (KB3099522). This update raises Exchange 2013 version number to 15.0.1156.6.

  • KB 3120594 Appointment on the Outlook calendar isn’t updated to a meeting when attendees are added
  • KB 3108345 “The app couldn’t be downloaded” error occurs when you try to install an application from the Intranet in Exchange Server 2013
  • KB 3108011 Error message occurs in Outlook after you change a single instance of a recurring meeting by using an iOS device
  • KB 3107781 Exchange ActiveSync device doesn’t keep messages for 30 days as configured
  • KB 3107379 Noderunner.exe consumes excessive CPU resources by parsing an attached document in Exchange Server 2013
  • KB 3107337 Mailbox migration from Exchange Server 2007 to Exchange Server 2013 is very slow
  • KB 3107291 Exception occurs when you run the Invoke-MonitoringProbe cmdlets to set probes for IMAP and POP3 in Exchange Server 2013
  • KB 3107205 “Custom error module does not recognize this error” error when OWA web parts fail to load
  • KB 3107174 Pages that use the People pop-up URL don’t load in Chrome when you access OWA or the Exchange Server Administration Center
  • KB 3106613 Outlook Web App shows partial contacts in an Exchange Server 2013 environment
  • KB 3106475 POP3 and IMAP4 are not supported to use TLS protocol 1.1 or 1.2 in Exchange Server 2013
  • KB 3106421 Very long URLs in an email message do not open in OWA in Internet Explorer
  • KB 3105760 Exchange Server 2016 mailbox server can be added to an Exchange Server 2013 DAG
  • KB 3105690 Outlook clients that use MAPI over HTTP to connect to Microsoft Exchange Server 2013 mailboxes are intermittently disconnected
  • KB 3105685 The lsass.exe process leaks an amount of handles in Exchange Server 2013
  • KB 3105654 Cannot edit Inbox rules in Outlook Web App by using Chrome
  • KB 3105625 ActiveSync device downloads emails while it’s in quarantine in an Exchange Server 2013 environment
  • KB 3105389 WSMan-InvalidShellID error when you create remote PowerShell sessions in an Exchange Server 2013 environment
  • KB 3100519 No responses are sent from a room mailbox when a booked meeting extends beyond the date you set in Exchange Server 2013
  • KB 3093866 The number of search results can’t be more than 250 when you search email messages in Exchange Server 2013
  • KB 3088911 Inline attachments are sent as traditional when you smart forward an HTML email in an iOS device in Exchange Server 2013
  • KB 3088487 IOPS Write increase causes email delivery delays in an Exchange Server 2013 environment
  • KB 3076376 IMAP clients that use Kerberos authentication protocol are continually prompted for credentials in Exchange Server 2013
  • KB 3068470 “Something went wrong” error in Outlook Web App and ECP in Exchange Server 2013
  • KB 3048372 Exchange Calendar items are shifted incorrectly when some Windows DST updates are applied
  • KB 2968265 OWA cannot be accessed after you upgrade Exchange Server 2013

 

Notes:

  • This CU introduces an important change in the mechanism how Exchange Management Shell sessions will be initiated as of Exchange 2013 CU11 (and to be introduced in Exchange 2016, as well), called Mailbox Anchoring. More on this later in this article.
  • When using Exchange hybrid deployments or Exchange Online Archiving (EOA), you are required to stay current (version N) or be one version behind (N-1).
  • Cumulative Update may include schema or Active Directory changes (e.g. Role-Based Access Control). Make sure you run PrepareSchema /PrepareAD.  If you want to speed up the Cumulative Update installation process, you can temporarily disable certificate revocation checking as described here.

Note that Cumulative Updates can be installed directly, i.e. no need to install RTM prior to installing Cumulative Updates. Note that once installed, you can’t uninstall a Cumulative Update nor any of the installed Exchange server roles. The order of upgrading servers is irrelevant, unlike with previous generations of Exchange.

Finally, and I can’t emphasize this enough: For any Hotfix, Rollup, Service Pack or Cumulative Update, I’d recommend to thoroughly test this in a test and acceptance environment first, prior to implementing it in production. When you lack such facilities, hold out a week or two and monitor the comments on the release article or TechNet forum for any issues.

You can download Exchange 2013 Cumulative Update 11 here; UM Language Packs can be found here.

MAILBOX ANCHORING
This CU introduces an important change in the administrative model. In short, you need to home your administrative mailbox on the Exchange platform level you want to administer Exchange from (mailbox anchoring), as you will connect (or be proxied) to an Exchange Management Shell (EMS) session on that host. In other words, use an administrative account with a mailbox on Exchange 2013 to administer Exchange 2013, use an admin mailbox on Exchange 2016 for Exchange 2016. The logic behind this is to work around mixed-version environment issues, as newer Exchange versions may introduce changes, like new or enhanced cmdlets but also deprecated functionality. New general recommendation is to keep arbitration mailboxes as well as administrative mailboxes on the most current version.

If the admin has no mailbox, or if it’s unavailable, arbitration mailboxes – primarily SystemMailbox{bb558c35-97f1-4cb9-8ff7-d53741dc928c} – are considered for hosting your EMS session. Also, that ‘Connected to <Server>’ message when you open up an EMS session will no longer always mean your EMS session is hosted on that server; it could mean your EMS session is being proxied through there, which can create challenges when you’re running multiple sites with low bandwidth links – you may need to move your admin mailbox around or create one for local administration to enjoy better response times. You can only discover which host your session runs on by inspecting the local environment, using elements like the env:COMPUTERNAME variable or [System.Net.Dns]::GetHostName().

Also, it might be wise to spread administrative mailboxes over different servers or databases, in case your arbitration mailboxes become unavailable together with that one administrative mailbox, as you need to recover one of those just so you can set up an EMS session. The last resort for running an EMS cmdlets – against all best practices and recommendations, as it bypasses Role-Based Access Control for example – is  to load the Exchange module using Add-PSSnapIn. But be advised, you may not have all required permissions, for example your admin account may not have direct Active Directory permissions (and which is one of the reasons you shouldn’t just load the snap-in under normal circumstances).

The Exchange Team put up a separate blog to explain this change in behavior here.