Number: AL19-009
Date: 14 May 2019
PURPOSE
An Alert is used to raise awareness of a recently disclosed Remote Code Execution vulnerability in the Microsoft Remote Desktop Services platform.
ASSESSMENT
Microsoft has released patches for a critical vulnerability in Microsoft Remote Desktop Services (RDS). The vulnerability allows a remote, unauthenticated actor to run arbitrary code on some Microsoft operating systems running RDS. This vulnerability is ‘wormable’, meaning that exploits of this vulnerability could automatically propagate from one vulnerable system to another.
The vulnerable operating systems are:
- Windows 7 for 32-bit Systems Service Pack 1
- Windows 7 for x64-based Systems Service Pack 1
- Windows Server 2008 for 32-bit Systems Service Pack 2
- Windows Server 2008 for 32-bit Systems Service Pack 2
- Windows Server 2008 for Itanium-Based Systems Service Pack 2
- Windows Server 2008 for x64-based Systems Service Pack 2
- Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)
- Windows Server 2008 R2 for Itanium-Based Systems Service Pack 1
- Windows Server 2008 R2 for x64-based Systems Service Pack 1
- Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)
- Windows XP SP3 x86
- Windows XP Professional x64 Edition SP2
- Windows XP Embedded SP3 x86
- Windows Server 2003 SP2 x86
- Windows Server 2003 x64 Edition SP2
SUGGESTED ACTION
- Install the latest updates for the vulnerable operating systems.
- Disable Remote Desktop Services if not required. If required, closely monitor network traffic and the logs of any vulnerable systems for suspicious activity.
- Enable Network Level Authentication (NLA) on systems running Windows 7, Windows Server 2008, and Windows Server 2008 R2. This is a partial mitigation which will prevent the spread of the malware.
- Block TCP port 3389 on the firewall, if possible. This will prevent unauthorized access from the Internet.
REFERENCES
Microsoft advisory: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-0708
Microsoft advisory for legacy operating systems (Windows XP and Server 2003): https://support.microsoft.com/en-ca/help/4500705/customer-guidance-for-cve-2019-0708
Microsoft blog post: https://blogs.technet.microsoft.com/msrc/2019/05/14/prevent-a-worm-by-updating-remote-desktop-services-cve-2019-0708/
NOTE TO READERS
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