Microsoft February 2021 Patch Tuesday fixes 56 bugs, including Windows zero-day
Microsoft has released today its monthly batch of security updates, known as Patch Tuesday. This month, the OS maker has fixed 56 security vulnerabilities, including a Windows bug that was being exploited in the wild before today’s patches.
Tracked as CVE-2021-1732, the Windows zero-day is an elevation of privelege bug in Win32k, a core component of the Windows operating system.
The bug was exploited after attackers gained access to a Windows system in order to obtain SYSTEM-level access.
Details about the attacks where this bug was used were not revealed. Microsoft credited three security researchers from Chinese security firm DBAPPSecurity with discovering the attacks where this zero-day was employed.
Many bug details went public
Besides the zero-day, this month’s Patch Tuesday also stands out because of the high number of vulnerabilities whose details were made public even before patches were available.
In total, six Microsoft product bugs had their details posted online before today’s patches. This included:
CVE-2021-1721 – .NET Core and Visual Studio Denial of Service Vulnerability
CVE-2021-1733 – Sysinternals PsExec Elevation of Privilege Vulnerability
CVE-2021-26701 – .NET Core Remote Code Execution Vulnerability
CVE-2021-1727 – Windows Installer Elevation of Privilege Vulnerability
CVE-2021-24098 – Windows Console Driver Denial of Service Vulnerability
CVE-2021-24106 – Windows DirectX Information Disclosure Vulnerability
The good news is that none of these bugs were exploited by attackers, despite their details being posted online.
Warning about TCP/IP bugs
But that’s not all. This month, Microsoft has also released fixes for three vulnerabilities in the Windows TCP/IP stack, which allows the operating system to connect to the internet.
Two of these bugs (CVE-2021-24074, CVE-2021-24094) apply fixes for remote code execution vulnerabilities that could allow attackers to take over Windows systems remotely.
A third bug (CVE-2021-24086) could be used to crash Windows devices.
“The two RCE vulnerabilities are complex which make it difficult to create functional exploits, so they are not likely [to be exploited] in the short term,” Microsoft said in a blog post specifically published to warn about these three issues.
“We believe attackers will be able to create DoS exploits much more quickly and expect all three issues might be exploited with a DoS attack shortly after release,” the company added. “Thus, we recommend customers move quickly to apply Windows security updates this month.”
Of all Windows systems, Windows Server instances are the ones most likely to be susceptible to attacks, as many are used to host web servers or cloud infrastructure and are almost certainly connected to the internet at all times and exposed to attacks.
“It is essential that customers apply Windows updates to address these vulnerabilities as soon as possible,” Microsoft said.
If patches can’t be applied right away, various workarounds can be deployed, details in each vulnerability’s advisory.
Below are additional details about today’s Microsoft Patch Tuesday and security updates released by other tech companies:
Microsoft’s official Security Update Guide portal lists all security updates in a filterable table.
ZDNet has published this file listing all this month’s security advisories on one single page.
Adobe’s security updates are detailed here.
SAP security updates are available here.
Intel security updates are available here.
VMWare security updates are available here.
Chrome 88 security updates are detailed here.
Android security updates are available here.
Tag
CVE ID
CVE Title
.NET Core
CVE-2021-26701
.NET Core Remote Code Execution Vulnerability
.NET Core
CVE-2021-24112
.NET Core Remote Code Execution Vulnerability
.NET Core & Visual Studio
CVE-2021-1721
.NET Core and Visual Studio Denial of Service Vulnerability
.NET Framework
CVE-2021-24111
.NET Framework Denial of Service Vulnerability
Azure IoT
CVE-2021-24087
Azure IoT CLI extension Elevation of Privilege Vulnerability
Developer Tools
CVE-2021-24105
Package Managers Configurations Remote Code Execution Vulnerability
Microsoft Azure Kubernetes Service
CVE-2021-24109
Microsoft Azure Kubernetes Service Elevation of Privilege Vulnerability
Microsoft Dynamics
CVE-2021-24101
Microsoft Dataverse Information Disclosure Vulnerability
Microsoft Dynamics
CVE-2021-1724
Microsoft Dynamics Business Central Cross-site Scripting Vulnerability
Microsoft Edge for Android
CVE-2021-24100
Microsoft Edge for Android Information Disclosure Vulnerability
Microsoft Exchange Server
CVE-2021-24085
Microsoft Exchange Server Spoofing Vulnerability
Microsoft Exchange Server
CVE-2021-1730
Microsoft Exchange Server Spoofing Vulnerability
Microsoft Graphics Component
CVE-2021-24093
Windows Graphics Component Remote Code Execution Vulnerability
Microsoft Office Excel
CVE-2021-24067
Microsoft Excel Remote Code Execution Vulnerability
Microsoft Office Excel
CVE-2021-24068
Microsoft Excel Remote Code Execution Vulnerability
Microsoft Office Excel
CVE-2021-24069
Microsoft Excel Remote Code Execution Vulnerability
Microsoft Office Excel
CVE-2021-24070
Microsoft Excel Remote Code Execution Vulnerability
Microsoft Office SharePoint
CVE-2021-24071
Microsoft SharePoint Information Disclosure Vulnerability
Microsoft Office SharePoint
CVE-2021-1726
Microsoft SharePoint Spoofing Vulnerability
Microsoft Office SharePoint
CVE-2021-24066
Microsoft SharePoint Remote Code Execution Vulnerability
Microsoft Office SharePoint
CVE-2021-24072
Microsoft SharePoint Server Remote Code Execution Vulnerability
Microsoft Teams
CVE-2021-24114
Microsoft Teams iOS Information Disclosure Vulnerability
Microsoft Windows Codecs Library
CVE-2021-24081
Microsoft Windows Codecs Library Remote Code Execution Vulnerability
Microsoft Windows Codecs Library
CVE-2021-24091
Windows Camera Codec Pack Remote Code Execution Vulnerability
Role: DNS Server
CVE-2021-24078
Windows DNS Server Remote Code Execution Vulnerability
Role: Hyper-V
CVE-2021-24076
Microsoft Windows VMSwitch Information Disclosure Vulnerability
Role: Windows Fax Service
CVE-2021-24077
Windows Fax Service Remote Code Execution Vulnerability
Role: Windows Fax Service
CVE-2021-1722
Windows Fax Service Remote Code Execution Vulnerability
Skype for Business
CVE-2021-24073
Skype for Business and Lync Spoofing Vulnerability
Skype for Business
CVE-2021-24099
Skype for Business and Lync Denial of Service Vulnerability
SysInternals
CVE-2021-1733
Sysinternals PsExec Elevation of Privilege Vulnerability
System Center
CVE-2021-1728
System Center Operations Manager Elevation of Privilege Vulnerability
Visual Studio
CVE-2021-1639
Visual Studio Code Remote Code Execution Vulnerability
Visual Studio Code
CVE-2021-26700
Visual Studio Code npm-script Extension Remote Code Execution Vulnerability
Windows Address Book
CVE-2021-24083
Windows Address Book Remote Code Execution Vulnerability
Windows Backup Engine
CVE-2021-24079
Windows Backup Engine Information Disclosure Vulnerability
Windows Console Driver
CVE-2021-24098
Windows Console Driver Denial of Service Vulnerability
Windows Defender
CVE-2021-24092
Microsoft Defender Elevation of Privilege Vulnerability
Windows DirectX
CVE-2021-24106
Windows DirectX Information Disclosure Vulnerability
Windows Event Tracing
CVE-2021-24102
Windows Event Tracing Elevation of Privilege Vulnerability
Windows Event Tracing
CVE-2021-24103
Windows Event Tracing Elevation of Privilege Vulnerability
Windows Installer
CVE-2021-1727
Windows Installer Elevation of Privilege Vulnerability
Windows Kernel
CVE-2021-24096
Windows Kernel Elevation of Privilege Vulnerability
Windows Kernel
CVE-2021-1732
Windows Win32k Elevation of Privilege Vulnerability
Windows Kernel
CVE-2021-1698
Windows Win32k Elevation of Privilege Vulnerability
Windows Mobile Device Management
CVE-2021-24084
Windows Mobile Device Management Information Disclosure Vulnerability
Windows Network File System
CVE-2021-24075
Windows Network File System Denial of Service Vulnerability
Windows PFX Encryption
CVE-2021-1731
PFX Encryption Security Feature Bypass Vulnerability
Windows PKU2U
CVE-2021-25195
Windows PKU2U Elevation of Privilege Vulnerability
Windows PowerShell
CVE-2021-24082
Microsoft.PowerShell.Utility Module WDAC Security Feature Bypass Vulnerability
Windows Print Spooler Components
CVE-2021-24088
Windows Local Spooler Remote Code Execution Vulnerability
Windows Remote Procedure Call
CVE-2021-1734
Windows Remote Procedure Call Information Disclosure Vulnerability
Windows TCP/IP
CVE-2021-24086
Windows TCP/IP Denial of Service Vulnerability
Windows TCP/IP
CVE-2021-24074
Windows TCP/IP Remote Code Execution Vulnerability
Windows TCP/IP
CVE-2021-24094
Windows TCP/IP Remote Code Execution Vulnerability
Windows Trust Verification API
CVE-2021-24080
Windows Trust Verification API Denial of Service Vulnerability More
