May 2024 Patch Tuesday: Two Zero-Days Among 61 Vulnerabilities Addressed

Microsoft has released security updates for 61 vulnerabilities in its May 2024 Patch Tuesday rollout. There are two zero-day vulnerabilities patched, affecting Windows MSHTML (CVE-2024-30040) and Desktop Window Manager (DWM) Core Library (CVE-2024-30051), and one Critical vulnerability patched affecting Microsoft SharePoint Server (CVE-2024-30044).

May 2024 Risk Analysis

This month’s leading risk type is remote code execution (44%) followed by elevation of privilege (28%) and information disclosure (11%). This follows the trend set last month.

Windows products received the most patches this month with 47, followed by Extended Security Update (ESU) with 25 and Developer Tools with 4.

Zero-Day Affecting Windows MSHTML Platform

CVE-2024-30040 is a security feature bypass vulnerability affecting the Microsoft Windows MSHTML platform with a severity rating of Important and a CVSS score of 8.8. Successful exploitation of this vulnerability would allow the attacker to circumvent the mitigation previously added to protect against an Object Linking and Embedding attack, and download a malicious payload to an unsuspecting host.

That malicious payload can lead to malicious embedded content and a victim user potentially clicking on that content, resulting in undesirable consequences. The MSHTML platform is used throughout Microsoft 365 and Microsoft Office products. Due to the exploitation status of this vulnerability, patching should be done immediately to prevent exploitation.

Table 1. Critical vulnerabilities in Windows MSHTML Platform

Zero-day Affecting Desktop Window Manager Core Library

CVE-2024-30051 is an elevation of privilege vulnerability affecting Microsoft Windows Desktop Window Manager (DWM) Core Library with a severity rating of Important and a CVSS score of 7.8. This library is responsible for interacting with applications in order to display content to the user. Successful exploitation of this vulnerability would allow the attacker to gain SYSTEM-level permissions.

CrowdStrike has detected active exploitation attempts of this vulnerability. Due to this exploitation status, patching should be done immediately to prevent exploitation.

Table 2. Critical vulnerabilities in Windows Desktop Window Manager Core Library

Critical Vulnerability Affecting Microsoft SharePoint Server

CVE-2024-30044 is a Critical remote code execution (RCE) vulnerability affecting Microsoft Windows Hyper-V with a CVSS score of 8.1. Successful exploitation of this vulnerability would allow an authenticated attacker with Site Owner privileges to inject and execute arbitrary code on the SharePoint Server.

Table 3. Critical vulnerabilities in Microsoft SharePoint Server

Not All Relevant Vulnerabilities Have Patches: Consider Mitigation Strategies

As we have learned with other notable vulnerabilities, such as Log4j, not every highly exploitable vulnerability can be easily patched. As is the case for the ProxyNotShell vulnerabilities, it’s critically important to develop a response plan for how to defend your environments when no patching protocol exists.

Regular review of your patching strategy should still be a part of your program, but you should also look more holistically at your organization's methods for cybersecurity and improve your overall security posture.

The CrowdStrike Falcon® platform regularly collects and analyzes trillions of endpoint events every day from millions of sensors deployed across 176 countries. Watch this demo to see the Falcon platform in action.

Learn More

Learn more about how CrowdStrike Falcon® Exposure Management can help you quickly and easily discover and prioritize vulnerabilities and other types of exposures here.

About CVSS Scores

The Common Vulnerability Scoring System (CVSS) is a free and open industry standard that CrowdStrike and many other cybersecurity organizations use to assess and communicate software vulnerabilities’ severity and characteristics. The CVSS Base Score ranges from 0.0 to 10.0, and the National Vulnerability Database (NVD) adds a severity rating for CVSS scores. Learn more about vulnerability scoring in this article.

Additional Resources

• For more information on which products are in Microsoft’s Extended Security Updates program, refer to the vendor guidance here.
• Read the CrowdStrike 2024 Global Threat Report to learn how the threat landscape has shifted in the past year and understand the adversary behavior driving these shifts.
• See how Falcon Exposure Management can help you discover and manage vulnerabilities and other exposures in your environments.
• Learn how CrowdStrike’s external attack surface module, CrowdStrike® Falcon Surface™, can discover unknown, exposed and vulnerable internet-facing assets, enabling security teams to stop adversaries in their tracks.
• Learn how CrowdStrike Falcon® Identity Protection products can stop workforce identity threats faster.
• Make prioritization painless and efficient. Watch how CrowdStrike Falcon® Spotlight enables IT staff to improve visibility with custom filters and team dashboards.
• Test CrowdStrike next-gen antivirus for yourself with a free trial of CrowdStrike® Falcon Prevent™.