Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256
===========================================================================
AUSCERT External Security Bulletin Redistribution
ESB-2020.0454
Updated Microsoft guidance about upcoming changes to LDAP
Channel Binding and LDAP Signing
7 February 2020
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: Active Directory
Publisher: Microsoft
Operating System: Windows
Resolution: None
Original Bulletin:
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/ADV190023
- --------------------------BEGIN INCLUDED TEXT--------------------
************************************************************************************
Title: Microsoft Security Update Minor Revisions
Issued: February 4, 2020
************************************************************************************
Summary
=======
The following advisory has undergone a minor revision increment:
* ADV190023
Revision Information:
=====================
- ADV190023 | Microsoft Guidance for Enabling LDAP Channel Binding and LDAP
Signing
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/ADV190023
- Reason for Revision: In the Recommended Actions section, added information that
details what will be included in the March 2020 updates to enable hardening LDAP
Channel Binding and LDAP Signing. Included information about a future monthly
update that will LDAP signing and channel binding on domain controllers
configured with default values for those settings. These are informational
changes only.
- Originally posted: August 13, 2019
- Updated: February 4, 2020
- Aggregate CVE Severity Rating: N/A
- Version: 1.3
Executive Summary:
=====================
LDAP channel binding and LDAP signing provide ways to increase the security for
communications between LDAP clients and Active Directory domain controllers. A
set of unsafe default configurations for LDAP channel binding and LDAP signing
exist on Active Directory Domain Controllers that let LDAP clients communicate
with them without enforcing LDAP channel binding and LDAP signing. This can open
Active directory domain controllers to elevation of privilege vulnerabilities.
This advisory addresses the issue by recommending a new set of safe default
configurations for LDAP channel binding and LDAP signing on Active Directory
Domain Controllers that supersedes the original unsafe configuration.
Recommended Actions:
=====================
Windows Updates in March 2020 add new audit events, additional logging, and a
remapping of Group Policy values that will enable hardening LDAP Channel Binding
and LDAP Signing. The March 2020 updates do not make changes to LDAP signing or
channel binding policies or their registry equivalent on new or existing domain
controllers.
A further future monthly update, anticipated for release the second half of
calendar year 2020, will enable LDAP signing and channel binding on domain
controllers configured with default values for those settings.
Administrators can prevent the feature update from making those change either by
enabling LDAP signing and channel binding NOW or by configuring non-default values
prior to installing updates that enable LDAP signing and channel binding by
default.
When the March 2020 Windows updates become available, customers will be notified
via a revision to this advisory. If you wish to be notified when these update
are released, we recommend that you register for the security notifications mailer
to be alerted of content changes to this advisory. See Microsoft Technical Security
Notifications. In the meantime, we strongly advise customers to take the following
steps at the earliest opportunity:
- - Configure your systems to help make LDAP channel binding and LDAP signing on
Active Directory Domain Controllers more secure.
- - Find and fix any application compatibility issues in the environment.
Other Information
=================
Recognize and avoid fraudulent email to Microsoft customers:
=============================================================
If you receive an email message that claims to be distributing
a Microsoft security update, it is a hoax that may contain
malware or pointers to malicious websites. Microsoft does
not distribute security updates via email.
The Microsoft Security Response Center (MSRC) uses PGP to digitally
sign all security notifications. However, PGP is not required for
reading security notifications, reading security bulletins, or
installing security updates. You can obtain the MSRC public PGP key
at <https://technet.microsoft.com/security/dn753714>.
********************************************************************
THE INFORMATION PROVIDED IN THIS MICROSOFT COMMUNICATION IS
PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT
DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING
THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE.
IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE
LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT,
INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL
DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN
ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY
FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING
LIMITATION MAY NOT APPLY.
********************************************************************
- --------------------------END INCLUDED TEXT--------------------
You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.
NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members. As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.
NOTE: This is only the original release of the security bulletin. It may
not be updated when updates to the original are made. If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.
Contact information for the authors of the original document is included
in the Security Bulletin above. If you have any questions or need further
information, please contact them directly.
Previous advisories and external security bulletins can be retrieved from:
https://www.auscert.org.au/bulletins/
===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072
Internet Email: auscert@auscert.org.au
Facsimile: (07) 3365 7031
Telephone: (07) 3365 4417 (International: +61 7 3365 4417)
AusCERT personnel answer during Queensland business hours
which are GMT+10:00 (AEST).
On call after hours for member emergencies only.
===========================================================================
-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967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=OiU5
-----END PGP SIGNATURE-----