Yesterday Microsoft released monthly system updates. CVE-2020-16898 | Windows TCP/IP Remote Code Execution Vulnerability is the one which is critical and you may need to to patch your systems as soon as possible.
Microsoft says: A remote code execution vulnerability exists when the Windows TCP/IP stack improperly handles ICMPv6 Router Advertisement packets. An attacker who successfully exploited this vulnerability could gain the ability to execute code on the target server or client. To exploit this vulnerability, an attacker would have to send specially crafted ICMPv6 Router Advertisement packets to a remote Windows computer. The update addresses the vulnerability by correcting how the Windows TCP/IP stack handles ICMPv6 Router Advertisement packets.
If you can’t install the patch then there’s a workaround for you. You can disable ICMPv6 RDNSS, to prevent attackers from exploiting the vulnerability, with the PowerShell command below. This workaround is only available for Windows 1709 and above.
Disable ICMPv6 RDNSS.
netsh int ipv6 set int *INTERFACENUMBER* rabaseddnsconfig=disable
Note: No reboot is needed after making the change.
So far the following systems are affected by this vulnerability.
- Windows 10 Version 1709 for 32-bit Systems
- Windows 10 Version 1709 for ARM64-based Systems
- Windows 10 Version 1709 for x64-based Systems
- Windows 10 Version 1803 for 32-bit Systems
- Windows 10 Version 1803 for ARM64-based Systems
- Windows 10 Version 1803 for x64-based Systems
- Windows 10 Version 1809 for 32-bit Systems
- Windows 10 Version 1809 for ARM64-based Systems
- Windows 10 Version 1809 for x64-based Systems
- Windows 10 Version 1903 for 32-bit Systems
- Windows 10 Version 1903 for ARM64-based Systems
- Windows 10 Version 1903 for x64-based Systems
- Windows 10 Version 1909 for 32-bit Systems
- Windows 10 Version 1909 for ARM64-based Systems
- Windows 10 Version 1909 for x64-based Systems
- Windows 10 Version 2004 for 32-bit Systems
- Windows 10 Version 2004 for ARM64-based Systems
- Windows 10 Version 2004 for x64-based Systems
- Windows Server 2019
- Windows Server 2019 (Server Core installation)
- Windows Server, version 1903 (Server Core installation)
- Windows Server, version 1909 (Server Core installation)
- Windows Server, version 2004 (Server Core installation)