Microsoft has announced a critical Remote Desktop Protocol (RDP) security vulnerability. RDP on Microsoft Server 2008/2008 R2 and Windows 7 are affected. Microsoft has also issued patches for End-of-Life operating systems Windows Server 2003 and Windows XP.
An unauthenticated attacker can exploit this vulnerability by connecting to the target system using the Remote Desktop Protocol (RDP) and sending specially crafted requests. This vulnerability is pre-authentication and requires no user interaction.
The RDP NLA (network level authentication) security setting mitigates this vulnerability from unauthenticated external attackers and it is the default for our Windows VPS. However, some clients may have disabled NLA.
The RDP NLA security setting can be found by going to the following location in Windows.
Control Panel > System > Remote settings > allow remote connections to this computer > [check] allow connections only from computers running Remote Desktop with Network Level Authentication (recommended)
All Windows VPS clients are recommended to update their VPS as soon as possible as well as double check to ensure the RDP NLA higher security setting is enabled.
Windows VPS can be updated by going to “Control Panel > Windows Update”.
We have received some reports from customers who are receiving a Windows Remote Desktop Connection (RDP) authentication error connecting to their VPS. This error is coming from a forced RDP client security update released from Microsoft in March 2018 that is now being enforced. The following error is realized when connecting from a patched client (home or work) computer to an unpatched Windows VPS server. Customers who have not updated their VPS since February 2018 may encounter the RDP authentication error and be prevented from connecting to their VPS temporarily.
As a temporary workaround you may follow these instructions to regain access to the VPS. The Windows VPS will need to be updated and restarted at your next convenience so that it has the same security update.
Microsoft released new Windows updates this week. Looking at the list of updates this month there is an important Windows RDP service security vulnerability announced. An attacker who successfully exploited this vulnerability could cause the RDP service on the target VPS to stop responding. There are also other important security updates and all should be done at the next earliest convenience.
We advise using the pre-installed Chrome browser (which auto updates) and minimizing your web browsing from your VPS for added security.