Like the previously-fixed ‘BlueKeep’ vulnerability (CVE-2019-0708), these two vulnerabilities are also ‘wormable’, meaning that any future malware that exploits these could propagate from vulnerable computer to vulnerable computer without user interaction.
The affected versions of Windows are Windows 7 SP1, Windows Server 2008 R2 SP1, Windows Server 2012, Windows 8.1, Windows Server 2012 R2, and all supported versions of Windows 10, including server versions.
Windows XP, Windows Server 2003, and Windows Server 2008 are not affected, nor is the Remote Desktop Protocol (RDP) itself affected.
These vulnerabilities were discovered by Microsoft during hardening of Remote Desktop Services. At this time, Microsoft have no evidence that these vulnerabilities were known to any third party.
It is important that affected systems are patched as quickly as possible because of the elevated risks associated with wormable vulnerabilities like these, and downloads for these can be found in the Microsoft Security Update Guide. Customers who have automatic updates enabled are automatically protected by these fixes.
There is partial mitigation on affected systems that have Network Level Authentication enabled. The affected systems are mitigated against ‘wormable’ malware or advanced malware threats that could exploit the vulnerability, as NLA requires authentication before the vulnerability can be triggered.
However, affected systems are still vulnerable to Remote Code Execution exploitation if the attacker has valid credentials that can be used to successfully authenticate.
Patches available here
UK based technology professional, with an interest in computer security and telecoms.