JPCERT-AT-2021-0017
                                                             JPCERT/CC
                                                            2021-04-14

                 <<< JPCERT/CC Alert 2021-04-14 >>>

           Microsoft Releases April 2021 Security Updates

       https://www.jpcert.or.jp/english/at/2021/at210013.html


I. Overview
Microsoft has released April 2021 Security Updates to address the
vulnerabilities in their products. Remote attackers leveraging
these vulnerabilities may be able to execute arbitrary code. It is
recommended to check the information provided by Microsoft and
apply the updates.

    Microsoft Corporation
    April 2021 Security Updates
    https://msrc.microsoft.com/update-guide/en-us/releaseNote/2021-Apr

    Microsoft Corporation
    Release Notes
    https://msrc.microsoft.com/update-guide/releaseNote

According to Microsoft, the Win32k elevation of privilege vulnerability
CVE-2021-28310 has been confirmed to be exploited in the wild. Please
consider applying the security update programs as soon as possible.

Also, security updates for new vulnerabilities of Exchange Server have
been released. Although Microsoft is not aware of any active exploits
in the wild, it is recommended to install these updates immediately.

    Microsoft The_Exchange_Team
    Released: April 2021 Exchange Server Security Updates
    https://techcommunity.microsoft.com/t5/exchange-team-blog/released-april-2021-exchange-server-security-updates/ba-p/2254617


II. Solution
Please apply the security update programs through Microsoft Update,
Windows Update, etc. as soon as possible.

    Microsoft Update Catalog
    https://www.catalog.update.microsoft.com/

    Windows Update: FAQ
    https://support.microsoft.com/en-us/help/12373/windows-update-faq


III. References
    Microsoft Corporation
    April 2021 Security Updates
    https://msrc.microsoft.com/update-guide/en-us/releaseNote/2021-Apr

    Microsoft Corporation
    Win32k Elevation of Privilege Vulnerability
    https://msrc.microsoft.com/update-guide/en-us/vulnerability/CVE-2021-28310

    Microsoft Corporation
    April 2021 Update Tuesday packages now available
    https://msrc-blog.microsoft.com/2021/04/13/april-2021-update-tuesday-packages-now-available/


If you have any information regarding this alert, please contact
JPCERT/CC.

======================================================================
JPCERT Coordination Center (Early Warning Group)
MAIL: ew-info@jpcert.or.jp
https://www.jpcert.or.jp/english/