
August Patch Tuesday 2021 Fixes 44 Vulnerabilities Including Weaponized Threat
August Patch Tuesday 2021 is officially here. See the latest Microsoft updates, vulnerabilities, and critical patches of the month.
Microsoft Releases August 2021 Patch Tuesday Fixes
There are 7 Critical and 37 Important fixes in this August Patch Tuesday for Microsoft Windows and Windows components, Office, .NET Core and Visual Studio, Windows Defender, Windows Update and Update Assistant, Azure, and Microsoft Dynamics.
Year 2 Extended Support – Windows 7 and Windows Server 2008 (including R2) have received some updates this month, with one currently Weaponized.
- Windows 7 – 4 Critical and 8 Important vulnerabilities fixed
- Windows 2008 R2 – 4 Critical and 9 Important vulnerabilities fixed
Robert Brown, Head of Customer Success for Syxsense said, “There are a number of extremely serious threats to deal with this month, and although there are less than half the number we have been facing just a couple months ago, it has never been more important to deploy these update to protect your environment.”
Top August 2021 Patches and Vulnerabilities
Based on the Vendor Severity and CVSS Score, we have made a few recommendations below. As usual, we recommend entering the CVE numbers below into your patch management solution and deploying as soon as possible.
1. CVE-2021-36948: Windows Update Medic Service Elevation of Privilege Vulnerability
The vulnerability allows a local user to escalate privileges on the system, due to a boundary error within the Windows Update Medic Service. A local user can run a specially crafted program to execute arbitrary code with elevated privileges.
We are also extremely concerned as this was discovered by Microsoft Security Response Center (MSRC) / Microsoft Threat Intelligence Center which could indicate this would be turned into a ransomware attack.
Syxscore
- Vendor Severity: Important
- CVSS: 7.8
- Weaponized: Yes
- Public Aware: No
- Countermeasure: No
Syxscore Risk Alert
- Attack Vector: Local
- Attack Complexity: Low
- Privileges: Low
- User Interaction: None
- Scope (Jump Point): No
2. CVE-2021-34535: Remote Desktop Client Remote Code Execution Vulnerability
In the case of a Remote Desktop connection, an attacker with control of a Remote Desktop Server could trigger a remote code execution (RCE) on the machine when a victim connects to the attacking server with the vulnerable Remote Desktop Client.
In the case of Hyper-V, a malicious program running in a guest VM could trigger guest-to-host RCE by exploiting this vulnerability in the Hyper-V Viewer when a victim running on the host connects to the attacking Hyper-V guest.
Microsoft advise this exploit is more likely.
Syxscore
- Vendor Severity: Critical
- CVSS: 8.8
- Weaponized: No
- Public Aware: No
- Countermeasure: No
Syxscore Risk Alert
- Attack Vector: Network
- Attack Complexity: Low
- Privileges: None
- User Interaction: Required
- Scope (Jump Point): No
3. CVE-2021-36936: Windows Print Spooler Remote Code Execution Vulnerability
The vulnerability allows a remote attacker to execute arbitrary code on the target system and successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
Microsoft advise this exploit is more likely.
Syxscore
- Vendor Severity: Critical
- CVSS: 8.8
- Weaponised: No
- Public Aware: Yes
- Countermeasure: No
Syxscore Risk Alert
- Attack Vector: Network
- Attack Complexity: Low
- Privileges: Low
- User Interaction: None
- Scope (Jump Point): No
Syxsense Recommendations
Based on the vendor severity and CVSS Score, we have made a few recommendations below which you should prioritize this month. Please pay close attention to any of these which are publicly aware or weaponized.
CVE Reference | Description | Vendor Severity | CVSS Score | Weaponized | Public Aware | Countermeasure | Syxsense Recommended |
CVE-2021-36948 | Windows Update Medic Service Elevation of Privilege Vulnerability | Important | 7.8 | Yes | No | No | Yes |
CVE-2021-36936 | Windows Print Spooler Remote Code Execution Vulnerability | Critical | 8.8 | No | Yes | No | Yes |
CVE-2021-36942 | Windows LSA Spoofing Vulnerability | Important | 7.5 | No | Yes | No | Yes |
CVE-2021-34535 | Remote Desktop Client Remote Code Execution Vulnerability | Critical | 9.9 | No | No | No | Yes |
CVE-2021-34480 | Scripting Engine Memory Corruption Vulnerability | Critical | 6.8 | No | No | No | Yes |
CVE-2021-34530 | Windows Graphics Component Remote Code Execution Vulnerability | Critical | 7.8 | No | No | No | Yes |
CVE-2021-34534 | Windows MSHTML Platform Remote Code Execution Vulnerability | Critical | 6.8 | No | No | No | Yes |
CVE-2021-26432 | Windows Services for NFS ONCRPC XDR Driver Remote Code Execution Vulnerability | Critical | 9.8 | No | No | No | Yes |
CVE-2021-26424 | Windows TCP/IP Remote Code Execution Vulnerability | Critical | 9.9 | No | No | No | Yes |
CVE-2021-34524 | Microsoft Dynamics 365 (on-premises) Remote Code Execution Vulnerability | Important | 8.1 | No | No | No | Yes |
CVE-2021-34537 | Windows Bluetooth Service Elevation of Privilege Vulnerability | Important | 7.8 | No | No | No | Yes |
CVE-2021-36947 | Windows Print Spooler Remote Code Execution Vulnerability | Important | 8.8 | No | No | No | Yes |
CVE-2021-26423 | .NET Core and Visual Studio Denial of Service Vulnerability | Important | 7.5 | No | No | No | |
CVE-2021-34485 | .NET Core and Visual Studio Information Disclosure Vulnerability | Important | 5 | No | No | No | |
CVE-2021-34532 | ASP.NET Core and Visual Studio Information Disclosure Vulnerability | Important | 5.5 | No | No | No | |
CVE-2021-33762 | Azure Cycle Cloud Elevation of Privilege Vulnerability | Important | 7 | No | No | No | |
CVE-2021-36943 | Azure Cycle Cloud Elevation of Privilege Vulnerability | Important | 4 | No | No | No | |
CVE-2021-26430 | Azure Sphere Denial of Service Vulnerability | Important | 6 | No | No | No | |
CVE-2021-26429 | Azure Sphere Elevation of Privilege Vulnerability | Important | 7.7 | No | No | No | |
CVE-2021-26428 | Azure Sphere Information Disclosure Vulnerability | Important | 4.4 | No | No | No | |
CVE-2021-36949 | Microsoft Azure Active Directory Connect Authentication Bypass Vulnerability | Important | 7.1 | No | No | No | |
CVE-2021-36950 | Microsoft Dynamics 365 (on-premises) Cross-site Scripting Vulnerability | Important | 5.4 | No | No | No | |
CVE-2021-36946 | Microsoft Dynamics Business Central Cross-site Scripting Vulnerability | Important | 5.4 | No | No | No | |
CVE-2021-34478 | Microsoft Office Remote Code Execution Vulnerability | Important | 7.8 | No | No | No | |
CVE-2021-36940 | Microsoft SharePoint Server Spoofing Vulnerability | Important | 7.6 | No | No | No | |
CVE-2021-34471 | Microsoft Windows Defender Elevation of Privilege Vulnerability | Important | 7.8 | No | No | Yes | |
CVE-2021-36941 | Microsoft Word Remote Code Execution Vulnerability | Important | 7.8 | No | No | No | |
CVE-2021-34536 | Storage Spaces Controller Elevation of Privilege Vulnerability | Important | 7.8 | No | No | No | |
CVE-2021-36945 | Windows 10 Update Assistant Elevation of Privilege Vulnerability | Important | 7.3 | No | No | No | |
CVE-2021-36938 | Windows Cryptographic Primitives Library Information Disclosure Vulnerability | Important | 5.5 | No | No | No | |
CVE-2021-36927 | Windows Digital TV Tuner device registration application Elevation of Privilege Vulnerability | Important | 7.8 | No | No | No | |
CVE-2021-26425 | Windows Event Tracing Elevation of Privilege Vulnerability | Important | 7.8 | No | No | No | |
CVE-2021-34486 | Windows Event Tracing Elevation of Privilege Vulnerability | Important | 7.8 | No | No | No | |
CVE-2021-34487 | Windows Event Tracing Elevation of Privilege Vulnerability | Important | 7 | No | No | No | |
CVE-2021-34533 | Windows Graphics Component Font Parsing Remote Code Execution Vulnerability | Important | 7.8 | No | No | No | |
CVE-2021-36937 | Windows Media MPEG-4 Video Decoder Remote Code Execution Vulnerability | Important | 7.8 | No | No | No | |
CVE-2021-34483 | Windows Print Spooler Elevation of Privilege Vulnerability | Important | 7.8 | No | No | No | |
CVE-2021-26431 | Windows Recovery Environment Agent Elevation of Privilege Vulnerability | Important | 7.8 | No | No | No | |
CVE-2021-26433 | Windows Services for NFS ONCRPC XDR Driver Information Disclosure Vulnerability | Important | 7.5 | No | No | No | |
CVE-2021-36926 | Windows Services for NFS ONCRPC XDR Driver Information Disclosure Vulnerability | Important | 7.5 | No | No | No | |
CVE-2021-36932 | Windows Services for NFS ONCRPC XDR Driver Information Disclosure Vulnerability | Important | 7.5 | No | No | No | |
CVE-2021-36933 | Windows Services for NFS ONCRPC XDR Driver Information Disclosure Vulnerability | Important | 7.5 | No | No | No | |
CVE-2021-26426 | Windows User Account Profile Picture Elevation of Privilege Vulnerability | Important | 7 | No | No | No | |
CVE-2021-34484 | Windows User Profile Service Elevation of Privilege Vulnerability | Important | 7.8 | No | No | No | |
CVE-2021-30590 | Chromium: CVE-2021-30590 Heap buffer overflow in Bookmarks | High | N/A | No | No | No | |
CVE-2021-30591 | Chromium: CVE-2021-30591 Use after free in File System API | High | N/A | No | No | No | |
CVE-2021-30592 | Chromium: CVE-2021-30592 Out of bounds write in Tab Groups | High | N/A | No | No | No | |
CVE-2021-30593 | Chromium: CVE-2021-30593 Out of bounds read in Tab Strip | High | N/A | No | No | No | |
CVE-2021-30594 | Chromium: CVE-2021-30594 Use after free in Page Info UI | High | N/A | No | No | No | |
CVE-2021-30596 | Chromium: CVE-2021-30596 Incorrect security UI in Navigation | Medium | N/A | No | No | No | |
CVE-2021-30597 | Chromium: CVE-2021-30597 Use after free in Browser UI | Medium | N/A | No | No | No |
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