Microsoft security alert.

Advisory overview

Qualys Vulnerability R&D Lab has released new vulnerability checks in the Qualys Cloud Platform to protect organizations against 41 vulnerabilities that were fixed in 13 bulletins announced today by Microsoft. Customers can immediately audit their networks for these and other new vulnerabilities by accessing their Qualys subscription. Visit Qualys Security Blog to prioritize remediation.

Non-Qualys customers can audit their network for these and other vulnerabilities by signing up for a Qualys Free Trial, or by trying Qualys Community Edition.

Vulnerability details

Microsoft has released 13 security bulletins to fix newly discovered flaws in their software. Qualys has released the following checks for these new vulnerabilities:

• Microsoft SharePoint Enterprise Server Multiple Vulnerabilities February 2021

  Severity

  Critical 4

  Qualys ID

  110372

  Vendor Reference

  KB4493194, KB4493195, KB4493210, KB4493223

  CVE Reference

  CVE-2021-1726, CVE-2021-24066, CVE-2021-24071, CVE-2021-24072

  CVSS Scores

  Base 6.5 / Temporal 4.8

  Description

  Microsoft has released February 2021 security updates to fix multiple security vulnerabilities.

  This security update contains the following KBs:

  KB4493210
  KB4493223
  KB4493194
  KB4493195

  QID Detection Logic:
  This authenticated QID checks the file versions from the above Microsoft KB article with the versions on the affected SharePoint system.

  Consequence

  Successful exploitation allows an attacker to execute code remotely.

  Solution

  Refer to Microsoft Security Guidance for more details pertaining to this vulnerability.

  Patches:
  The following are links for downloading patches to fix these vulnerabilities:
  Microsoft Office and Microsoft Office Services and Web Apps Security Update February 2021

• Microsoft Office and Microsoft Office Services and Web Apps Security Update February 2021

  Severity

  Critical 4

  Qualys ID

  110373

  Vendor Reference

  KB4493192, KB4493196, KB4493204, KB4493211, KB4493222

  CVE Reference

  CVE-2021-24067, CVE-2021-24068, CVE-2021-24069, CVE-2021-24070

  CVSS Scores

  Base 6.8 / Temporal 5

  Description

  Microsoft has released February 2021 security updates to fix multiple security vulnerabilities.

  This security update contains the following KBs:

  KB4493211
  KB4493222
  KB4493196
  KB4493192
  KB4493204

  QID Detection Logic:
  This authenticated QID checks the file versions from the Microsoft advisory with the versions on the affected office system.

  Note: Office click-2-run and Office 365 installations need to be updated manually or need to be set to automatic update. There is no direct download for the patch.

  Consequence

  Successful exploitation allows an attacker to execute code remotely.

  Solution

  Refer to Microsoft Security Guidance, KB4493192, KB4493196, KB4493204, KB4493211, KB4493222 for more details pertaining to this vulnerability.

  Patches:
  The following are links for downloading patches to fix these vulnerabilities:
  Microsoft Office and Microsoft Office Services and Web Apps Security Update February 2021

• Microsoft Mitigation Guidance for TCP/IP IPv4 Source routing Applied (CVE-2021-24074)

  Severity

  Minimal 1

  Qualys ID

  45480

  Vendor Reference

  CVE-2021-24074

  CVE Reference

  N/A

  CVSS Scores

  Base / Temporal

  Description

  Mitigation for "CVE-2021-24074 TCP/IP Vulnerability" is applied on the host.

  QID Detection Logic (Authenticated):
  

  This QID checks for Windows registry key "HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parameters", posts this QID when value "DisableIPSourceRouting" is 2.
  

  Consequence

  NA

  Solution

  Please refer to the CVE-2021-24074 for more information

• Microsoft Visual Studio Security Update for February 2021

  Severity

  Critical 4

  Qualys ID

  91729

  Vendor Reference

  CVE-2021-1639

  CVE Reference

  CVE-2021-1639, CVE-2021-1721

  CVSS Scores

  Base 6.8 / Temporal 5

  Description

  Microsoft has released security update for Visual Studio which resolves multiple security vulnerabilities.

  Affected Software:
  Microsoft Visual Studio 2017 version 15.9 (includes 15.0 - 15.8)
  Microsoft Visual Studio 2019 version 16.4 (includes 16.0 - 16.3)
  Microsoft Visual Studio 2019 version 16.7 (includes 16.0 - 16.6)
  Microsoft Visual Studio 2019 version 16.8

  QID Detection Logic:Authenticated
  This QID detects vulnerable versions of Microsoft Visual Studio by checking file version of devenv.exe.

  Consequence

  Successful exploitation can affect confidentiality, integrity and availability.

  Solution

  Customers are advised to refer to CVE-2021-1639 for more information pertaining to this vulnerability.

  Patches:
  The following are links for downloading patches to fix these vulnerabilities:
  CVE-2021-1639 WIndows

• Microsoft Windows Servicing Stack Security Update February 2021

  Severity

  Medium 2

  Qualys ID

  91732

  Vendor Reference

  ADV990001

  CVE Reference

  N/A

  CVSS Scores

  Base 3.6 / Temporal 2.7

  Description

  Servicing stack updates improve the reliability of the update process to mitigate potential issues while installing the latest quality updates and feature updates. If you don't install the latest servicing stack update, there's a risk that your device can't be updated with the latest Microsoft security fixes.

  Microsoft has released Servicing Stack security updates for Windows.

  QID Detection Logic (Authenticated):
  This authenticated QID will check for file version of CbsCore.dll

  Consequence

  Successful exploitation may allow unauthorized disclosure of information, unauthorized modification or disruption of service.

  Solution

  Customers are advised to refer to advisory ADV990001 for more information.

  Patches:
  The following are links for downloading patches to fix these vulnerabilities:
  ADV990001

• Microsoft .NET Framework Denial of Service Vulnerability - February 2021

  Severity

  Critical 4

  Qualys ID

  91733

  Vendor Reference

  KB4578951, KB4601050, KB4601051, KB4601054, KB4601056, KB4601318, KB4601354, KB4601887, KB4602958, KB4602959, KB4602960, KB4602961, KB4603002, KB4603003, KB4603004, KB4603005

  CVE Reference

  CVE-2021-24111

  CVSS Scores

  Base 5 / Temporal 3.7

  Description

  A denial of service vulnerability exist in Microsoft .Net Framework.

  Following KBs are covered in this detection:
  KB4601056, KB4601318, KB4601354, KB4601887, KB4602958, KB4602959, KB4602960, KB4602961, KB4603002, KB4603003, KB4603004
  This security update is rated Important for supported versions of Microsoft .NET Framework.

  .NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2 and 4.8

  QID Detection Logic (Authenticated):
  - Checks for vulnerable version of System.web.dll for .Net Framework
  

  Consequence

  Successful exploitation allows attacker to cause denial of service vulnerability.
  

  Solution

  Customers are advised to refer to CVE-2021-24111 for more details pertaining to this vulnerability.
  

  Patches:
  The following are links for downloading patches to fix these vulnerabilities:
  CVE-2021-24111

• Microsoft Defender Elevation of Privilege Vulnerability February 2021

  Severity

  Critical 4

  Qualys ID

  91734

  Vendor Reference

  CVE-2021-24092

  CVE Reference

  CVE-2021-24092

  CVSS Scores

  Base 4.6 / Temporal 3.4

  Description

  Microsoft Defender is prone to Elevation of Privilege Vulnerability

  Affected Software:
  Microsoft System Center 2012 Endpoint Protection
  Microsoft Security Essentials
  Microsoft System Center 2012 R2 Endpoint Protection
  Microsoft System Center Endpoint Protection
  Windows Defender

  QID Detection Logic (Authenticated):
  Detection checks for mpengine.dll file version less than 1.1.17800.5

  Consequence

  Successful exploitation allows attacker to compromise the system.
  

  Solution

  Users are advised to check CVE-2021-24092 for more information.

  Patches:
  The following are links for downloading patches to fix these vulnerabilities:
  CVE-2021-24092

• Microsoft Windows TCP/IP Remote Code Execution Vulnerabilities

  Severity

  Urgent 5

  Qualys ID

  91738

  Vendor Reference

  CVE-2021-24074, CVE-2021-24086, CVE-2021-24094

  CVE Reference

  CVE-2021-24074, CVE-2021-24086, CVE-2021-24094

  CVSS Scores

  Base 7.5 / Temporal 6.2

  Description

  Microsoft released a set of fixes affecting Windows TCP/IP implementation that include two Critical Remote Code Execution (RCE) vulnerabilities (CVE-2021-24074,CVE-2021-24094) and an Important Denial of Service (DoS) vulnerability (CVE-2021-24086).

  All supported version of Windows are affected. The KB Articles associated with the update:
  KB4601345
  KB4601354
  KB4601366
  KB4601348
  KB4601349
  KB4601363
  KB4601360
  KB4601384
  KB4601347
  KB4601357
  KB4601319
  KB4601318
  KB4601315
  KB4601331
  

  This QID checks for the file version of tcpip.sys

  The following versions of tcpip.sys with their corresponding KBs are verified:
  KB4601345 - 10.0.17763.1757
  KB4601354 - 10.0.17134.2026
  KB4601366 - 6.0.6003.21039
  KB4601348 - 6.2.9200.23267
  KB4601349 - 6.3.9600.19935
  KB4601363 - 6.1.7601.24565
  KB4601360 - 6.0.6003.21039
  KB4601384 - 6.3.9600.19935
  KB4601347 - 6.1.7601.24565
  KB4601357 - 6.2.9200.23267
  KB4601319 - 10.0.19041.804
  KB4601318 - 10.0.14393.4225
  KB4601315 - 10.0.18362.1377
  KB4601331 - 10.0.10240.18841
  

  Consequence

  Successful exploitation allows attacker to execute remote code and compromise the system.

  Solution

  Customers are advised to refer to KB4601345
  KB4601354
  KB4601366
  KB4601348
  KB4601349
  KB4601363
  KB4601360
  KB4601384
  KB4601347
  KB4601357
  KB4601319
  KB4601318
  KB4601315
  KB4601331
  Note: To fix the issue, use Cumulative updates released in later months that supersede the KB4601318 must be installed for example KB5000803.Workaround:
  

  1. CVE-2021-24074 : Set sourceroutingbehavior to "drop"
  Use the following command:

  "netsh int ipv4 set global sourceroutingbehavior=drop"

  2. CVE-2021-24086 and CVE-2021-24094: Set global reassemblylimit to 0
  Use the following command:

  "Netsh int ipv6 set global reassemblylimit=0"
  

  Patches:
  The following are links for downloading patches to fix these vulnerabilities:
  Microsoft Security Update Guide Windows

• Microsoft Windows Security Update for February 2021

  Severity

  Critical 4

  Qualys ID

  91739

  Vendor Reference

  KB4601315, KB4601318, KB4601319, KB4601331, KB4601345, KB4601347, KB4601348, KB4601349, KB4601354, KB4601357, KB4601360, KB4601363, KB4601366, KB4601384

  CVE Reference

  CVE-2021-1698, CVE-2021-1727, CVE-2021-1731, CVE-2021-1734, CVE-2021-24075, CVE-2021-24076, CVE-2021-24079, CVE-2021-24080, CVE-2021-24081, CVE-2021-24082, CVE-2021-24083, CVE-2021-24084, CVE-2021-24088, CVE-2021-24091, CVE-2021-24093, CVE-2021-24096, CVE-2021-24098, CVE-2021-24102, CVE-2021-24103, CVE-2021-24106, CVE-2021-25195

  CVSS Scores

  Base 6.8 / Temporal 5

  Description

  Microsoft releases the security update for Windows February 2021

  The KB Articles associated with the update:
  KB4601345
  KB4601354
  KB4601366
  KB4601348
  KB4601349
  KB4601363
  KB4601360
  KB4601384
  KB4601347
  KB4601357
  KB4601319
  KB4601318
  KB4601315
  KB4601331
  

  This QID checks for the file version of ntoskrnl.exe

  The following versions of ntoskrnl.exe with their corresponding KBs are verified:
  KB4601345 - 10.0.17763.1757
  KB4601354 - 10.0.17134.2026
  KB4601366 - 6.0.6003.21045
  KB4601348 - 6.2.9200.23272
  KB4601349 - 6.3.9600.19939
  KB4601363 - 6.1.7601.24565
  KB4601360 - 6.0.6003.21045
  KB4601384 - 6.3.9600.19939
  KB4601347 - 6.1.7601.24565
  KB4601357 - 6.2.9200.23272
  KB4601319 - 10.0.19041.804
  KB4601318 - 10.0.14393.4225
  KB4601315 - 10.0.18362.1377
  KB4601331 - 10.0.10240.18841
  

  Consequence

  A remote attacker could exploit this vulnerability and execute code on the target system.

  Solution

  Please refer to the Security Update Guide for more information pertaining to these vulnerabilities.

  Patches:
  The following are links for downloading patches to fix these vulnerabilities:
  Microsoft Security Update Guide Windows

• Microsoft Windows DNS Server Remote Code Execution Vulnerability

  Severity

  Urgent 5

  Qualys ID

  91740

  Vendor Reference

  CVE-2021-24078

  CVE Reference

  CVE-2021-24078

  CVSS Scores

  Base 7.5 / Temporal 5.5

  Description

  A remote code execution vulnerability exists in Windows Domain Name System servers when they fail to properly handle requests.

  Affected Software:
  

  Windows Server 2012 R2 (Server Core installation) Windows Server 2012 R2 Windows Server 2012 (Server Core installation) Windows Server 2012 Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) Windows Server 2008 R2 for x64-based Systems Service Pack 1 Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation) Windows Server 2008 for x64-based Systems Service Pack 2 Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation) Windows Server 2008 for 32-bit Systems Service Pack 2 Windows Server 2016 (Server Core installation) Windows Server 2016 Windows Server, version 20H2 (Server Core Installation) Windows Server, version 2004 (Server Core installation) Windows Server, version 1909 (Server Core installation) Windows Server 2019 (Server Core installation) Windows Server 2019

  The KB Articles associated with the update:
  KB4601345
  KB4601366
  KB4601348
  KB4601349
  KB4601363
  KB4601360
  KB4601384
  KB4601347
  KB4601357
  KB4601319
  KB4601318
  KB4601315
  

  QID Detection Logic (Authenticated):
  

  This QID checks for the file version of dns.exe

  The following versions of dns.exe with their corresponding KBs are verified:
  KB4601345 - 10.0.17763.1757
  KB4601366 - 6.0.6003.21055
  KB4601348 - 6.2.9200.23284
  KB4601349 - 6.3.9600.19939
  KB4601363 - 6.1.7601.24565
  KB4601360 - 6.0.6003.21055
  KB4601384 - 6.3.9600.19939
  KB4601347 - 6.1.7601.24565
  KB4601357 - 6.2.9200.23284
  KB4601319 - 10.0.19041.804
  KB4601318 - 10.0.14393.4225
  KB4601315 - 10.0.18362.1377
  

  Consequence

  An attacker who successfully exploited the vulnerability could run arbitrary code

  Solution

  Please refer to the Security Update Guide for more information pertaining to these vulnerabilities.

  Patches:
  The following are links for downloading patches to fix these vulnerabilities:
  Microsoft Security Update Guide

• Microsoft Windows Win32k Elevation of Privilege Vulnerability

  Severity

  Critical 4

  Qualys ID

  91741

  Vendor Reference

  CVE-2021-1732

  CVE Reference

  CVE-2021-1732

  CVSS Scores

  Base 4.6 / Temporal 3.8

  Description

  There is a vulnerability discovered in Microsoft Windows, which can be exploited by malicious users to gain escalated privileges.

  Affected Software:
  

  Windows Server, version 20H2 (Server Core Installation) Windows 10 Version 20H2 for ARM64-based Systems Windows 10 Version 20H2 for 32-bit Systems Windows 10 Version 20H2 for x64-based Systems Windows Server, version 2004 (Server Core installation) Windows 10 Version 2004 for x64-based Systems Windows 10 Version 2004 for ARM64-based Systems Windows 10 Version 2004 for 32-bit Systems Windows Server, version 1909 (Server Core installation) Windows 10 Version 1909 for ARM64-based Systems Windows 10 Version 1909 for x64-based Systems Windows 10 Version 1909 for 32-bit Systems Windows Server 2019 (Server Core installation) Windows Server 2019 Windows 10 Version 1809 for ARM64-based Systems Windows 10 Version 1809 for x64-based Systems Windows 10 Version 1809 for 32-bit Systems Windows 10 Version 1803 for ARM64-based Systems Windows 10 Version 1803 for x64-based Systems Windows 10 Version 1803 for 32-bit Systems

  The KB Articles associated with the update:
  KB4601345
  KB4601319
  KB4601315
  KB4601354
  

  This QID checks for the file version of win32kfull.sys

  The following versions of win32kfull.sys with their corresponding KBs are verified:
  KB4601345 - 10.0.17763.1757
  KB4601319 - 10.0.19041.804
  KB4601315 - 10.0.18362.1377
  KB4601354 - 10.0.17134.2026
  

  Consequence

  Successful exploitation may allow execution of arbitrary code with kernel privileges.

  Solution

  Please refer to the Security Update CVE-2021-1732 for more information pertaining to these vulnerabilities.

  Patches:
  The following are links for downloading patches to fix these vulnerabilities:
  Microsoft Security Update Guide

• Microsoft Windows Fax Service Remote Code Execution Vulnerabilities

  Severity

  Urgent 5

  Qualys ID

  91742

  Vendor Reference

  CVE-2021-1722, CVE-2021-24077

  CVE Reference

  CVE-2021-1722, CVE-2021-24077

  CVSS Scores

  Base 7.5 / Temporal 5.5

  Description

  Microsoft Windows Fax Service is exposed to two remote code execution vulnerabilities. (CVE-2021-1722,CVE-2021-24077)

  Vulnerabilities details are unknown at this time.

  
  Note:To exploit this vulnerability, the Windows Fax and Scan feature needs to be enabled, and the Fax service needs to be running. Systems that do not have the Fax service running are not vulnerable.

  Affected Software:
  All supported version of Windows are affected.

  The KB Articles associated with the update:
  KB4601345
  KB4601354
  KB4601366
  KB4601348
  KB4601349
  KB4601363
  KB4601360
  KB4601384
  KB4601347
  KB4601357
  KB4601319
  KB4601318
  KB4601315
  KB4601331
  

  This QID checks for the file version of fxssvc.exe

  The following versions of fxssvc.exe with their corresponding KBs are verified:
  KB4601345 - 10.0.17763.1757
  KB4601354 - 10.0.17134.2026
  KB4601366 - 6.0.6003.21045
  KB4601348 - 6.2.9200.23274
  KB4601349 - 6.3.9600.19941
  KB4601363 - 6.1.7601.24565
  KB4601360 - 6.0.6003.21045
  KB4601384 - 6.3.9600.19941
  KB4601347 - 6.1.7601.24565
  KB4601357 - 6.2.9200.23274
  KB4601319 - 10.0.19041.804
  KB4601318 - 10.0.14393.4225
  KB4601315 - 10.0.18362.1377
  KB4601331 - 10.0.10240.18841
  

  Consequence

  An attacker who successfully exploited the vulnerability could run arbitrary code

  Solution

  Please refer to the Security Update Guide for more information pertaining to these vulnerabilities.

  Patches:
  The following are links for downloading patches to fix these vulnerabilities:
  Microsoft Security Update Guide Windows

• Microsoft ASP.NET Core Security Update February 2021

  Severity

  Critical 4

  Qualys ID

  91743

  Vendor Reference

  CVE-2021-1721

  CVE Reference

  CVE-2021-1721, CVE-2021-24112

  CVSS Scores

  Base 7.5 / Temporal 5.5

  Description

  A denial of service vulnerability exists when .NET Core improperly handles web requests.
  This security update is rated Important for supported versions of .NET Core.

  Affected versions:
  Any .NET Core 2.1 , 3.1 or .NET 5.0 application running on .NET Core 2.1.25, 3.1.12 or .NET 5.0.3 or lower respectively.

  QID Detection Logic (Authenticated):
  The qid looks for sub directories under %programfiles%\dotnet\shared\Microsoft.NETCore.App, %programfiles(x86)%\dotnet\shared\Microsoft.NETCore.App and checks for vulnerable versions in .version file on Windows.
  QID Detection Logic (Authenticated):
  This QID will detect the vulnerable version of Microsoft ASP.NET Core by using commands:
  ls -d /usr/share/dotnet/shared/Microsoft.NETCore.App/*
  ls -d /usr/local/share/dotnet/shared/Microsoft.NETCore.App/*
  

  Consequence

  Successful exploitation allows attacker to bypass the security feature and allows set a second cookie with the name being percent encoded.

  Solution

  Customers are advised to refer to CVE-2021-1721 for more details pertaining to this vulnerability.

  Patches:
  The following are links for downloading patches to fix these vulnerabilities:
  CVE-2021-1721 MAC
  CVE-2021-1721 WIndows

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Platforms and Platform Identification

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For more information, customers may contact Qualys Technical Support.

About Qualys

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