Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Endpoint

8/13/2019
04:45 PM
Connect Directly
Twitter
LinkedIn
RSS
E-Mail
100%
0%

Microsoft Patches Wormable RCE Vulns in Remote Desktop Services

Similar to the now-patched 'BlueKeep' vulnerability, two flaws fixed today could let malware spread across vulnerable computers.

Microsoft today released 93 fixes and two advisories as part of its monthly Patch Tuesday update. Of these, 64 were categorized as Important in severity and 29 were ranked Critical.

Patching priority should be given to two "wormable" remote code execution (RCE) vulnerabilities that could allow future malware to spread across vulnerable machines without user interaction.

CVE-2019-1181 and CVE-2019-1182 affect Windows 8.1, Windows 7 SP1, Windows Server 2008 R2 SP1, Windows Server 2012, Windows Server 2012 R2, and all supported versions of Windows 10, including server versions. They do not affect Windows XP, Windows Server 2008, Windows Server 2008, or the Remote Desktop Protocol (RDP) itself. Like the BlueKeep RDP vulnerability patched this year, both could let an attacker remotely install and spread malware.

The vulnerabilities exist in Remote Desktop Services, formerly known as Terminal Services, when an unauthenticated attacker connects to a target system using RDP and sends specially crafted requests. Because they don't require authentication or user interaction, an attacker could install programs; view, edit, or delete data; or create new accounts with full user rights.

To exploit CVE-2019-1181 and CVE-2019-1182, an attacker would have to use RDP to send a specially crafted request to the target system's RDS. Today's update corrects how Remote Desktop Services handles connection requests. Neither bug has been seen in the wild.

"These vulnerabilities were discovered by Microsoft during hardening of Remote Desktop Services as part of our continual focus on strengthening the security of our products," writes Simon Pope, director of incident response for Microsoft's Security Response Center. "At this time, we have no evidence that these vulnerabilities were known to any third party."

Pope also points to a "partial mitigation" on affected systems with Network Level Authentication (NLA) enabled. Because NLA requires authentication before the flaw can be exploited, these systems are protected from wormable malware, he says. However, they are still vulnerable to RCE if attackers possess valid credentials they can use to authenticate.

Two additional vulnerabilities patched today, CVE-2019-1222 and CVE-2019-1226, are also Critical RCE bugs in RDS but, unlike the previously mentioned bugs, they're not wormable.

Those aside, patches issued today address bugs in Windows, Edge, Internet Explorer, Microsoft Office, Microsoft Office Services and Web Apps, ChakraCore, Azure DevOps Server, Visual Studio, Online Services, and Microsoft Dynamics. None were publicly known or under attack.

Another vulnerability worth noting is CVE-2019-1201, a Critical RCE bug in Microsoft Word resulting from improper handling of objects in memory. An attacker could exploit this by creating a specially crafted Word file and convincing a victim to open it, either by attaching it to an email or hosting it on a malicious website. Outlook's Reading/Preview Pane is an attack vector, meaning victims wouldn't have to open an attachment to be exploited; they could simply view the email. If successful, an attacker could achieve the same permissions a target user has on the system.

It was a big month for patching, especially RCE vulnerabilities: Microsoft also fixed RCE bugs in the Chakra Scripting Engine, Microsoft Graphics, Hyper-V, Outlook, Word, the Windows DHCP client, Scripting Engine, and the VBScript Engine.

Related Content:

Kelly Sheridan is the Staff Editor at Dark Reading, where she focuses on cybersecurity news and analysis. She is a business technology journalist who previously reported for InformationWeek, where she covered Microsoft, and Insurance & Technology, where she covered financial ... View Full Bio
 

Recommended Reading:

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
tdsan
50%
50%
tdsan,
User Rank: Ninja
8/15/2019 | 12:55:10 PM
Re: We talked about this before

Yes, we do the same thing but we do it at the router or firewall where the port on the outside is 3288 which is redirected to 3389, but we also limit who can access that port as well (ACLs that limit our local offices or we use a jump host with login credentials, but a valid point you made earlier.

Todd
Edge-DRsplash-10-edge-articles
7 Old IT Things Every New InfoSec Pro Should Know
Joan Goodchild, Staff Editor,  4/20/2021
News
Cloud-Native Businesses Struggle With Security
Robert Lemos, Contributing Writer,  5/6/2021
Commentary
Defending Against Web Scraping Attacks
Rob Simon, Principal Security Consultant at TrustedSec,  5/7/2021
Register for Dark Reading Newsletters
White Papers
Video
Cartoon
Current Issue
2021 Top Enterprise IT Trends
We've identified the key trends that are poised to impact the IT landscape in 2021. Find out why they're important and how they will affect you today!
Flash Poll
How Enterprises are Developing Secure Applications
How Enterprises are Developing Secure Applications
Recent breaches of third-party apps are driving many organizations to think harder about the security of their off-the-shelf software as they continue to move left in secure software development practices.
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2021-32606
PUBLISHED: 2021-05-11
In the Linux kernel 5.11 through 5.12.2, isotp_setsockopt in net/can/isotp.c allows privilege escalation to root by leveraging a use-after-free. (This does not affect earlier versions that lack CAN ISOTP SF_BROADCAST support.)
CVE-2021-3504
PUBLISHED: 2021-05-11
A flaw was found in the hivex library in versions before 1.3.20. It is caused due to a lack of bounds check within the hivex_open function. An attacker could input a specially crafted Windows Registry (hive) file which would cause hivex to read memory beyond its normal bounds or cause the program to...
CVE-2021-20309
PUBLISHED: 2021-05-11
A flaw was found in ImageMagick in versions before 7.0.11 and before 6.9.12, where a division by zero in WaveImage() of MagickCore/visual-effects.c may trigger undefined behavior via a crafted image file submitted to an application using ImageMagick. The highest threat from this vulnerability is to ...
CVE-2021-20310
PUBLISHED: 2021-05-11
A flaw was found in ImageMagick in versions before 7.0.11, where a division by zero ConvertXYZToJzazbz() of MagickCore/colorspace.c may trigger undefined behavior via a crafted image file that is submitted by an attacker and processed by an application using ImageMagick. The highest threat from this...
CVE-2021-20311
PUBLISHED: 2021-05-11
A flaw was found in ImageMagick in versions before 7.0.11, where a division by zero in sRGBTransformImage() in the MagickCore/colorspace.c may trigger undefined behavior via a crafted image file that is submitted by an attacker processed by an application using ImageMagick. The highest threat from t...