No mayday call necessary for the year’s fifth Patch Tuesday

The deluge of patches in April dried up substantially in May, as Microsoft on Tuesday released 59 patches touching 11 product families. Windows as usual takes the lion’s share of patches with 48, with the rest spread among .NET, 365 Apps for Enterprise, Azure, Bing Search for iOS, Dynamics 365, Intune, Office, Power BI, SharePoint, and Visual Studio. There is just one critical-severity issue, affecting SharePoint.

At patch time, two issues, both important-severity faults affecting Windows, are known to be under active exploit in the wild. Ten additional important-severity vulnerabilities in Windows and SharePoint are by the company’s estimation more likely to be exploited in the next 30 days. Eight of the issues are amenable to detection by Sophos protections, and we include information on those in a table below.

In addition to these patches, the release includes advisory information on six patches related to the Edge browser; two related to Visual Studio but managed by GitHub, not Microsoft; and four from Adobe. We don’t include advisories in the CVE counts and graphics below, but we provide information on all of them in an appendix at the end of the article. We are as usual including at the end of this post three other appendices listing all Microsoft’s patches, sorted by severity, by predicted exploitability, and by product family.

By the numbers

• Total Microsoft CVEs: 59
• Total Edge / Chrome advisory issues covered in update: 6
• Total non-Microsoft Visual Studio advisory issues covered in update: 2
• Total Adobe issues covered in update: 4
• Publicly disclosed: 2
• Exploited: 2
• Severity
  • Critical: 1
  • Important: 57
  • Moderate: 1
• Impact:
  • Remote Code Execution: 25
  • Elevation of Privilege: 17
  • Information Disclosure: 7
  • Spoofing: 4
  • Denial of Service: 3
  • Security Feature Bypass: 2
  • Tampering: 1

Figure 1: May continues the previous month’s emphasis on RCE issues, though all seven of Microsoft’s usual impact categories put in an appearance

Products

• Windows: 48
• Dynamics 365: 2
• SharePoint: 2
• Visual Studio: 2 (including one shared with .NET; in addition, two advisory issues apply to VS)
• .NET: 1 (shared with Visual Studio)
• 365 Apps for Enterprise: 1 (shared with Office)
• Azure: 1
• Bing Search for iOS: 1
• Intune: 1
• Office: 1 (shared with 365 Apps for Enterprise)
• Power BI: 1

Figure 2: Windows takes the overwhelming number of May patches, but only SharePoint has a critical-severity issue to manage

Notable May updates and themes

In addition to the issues discussed above, a few specific items merit attention.

CVE-2024-4559 – Chromium: CVE-2024-4671 Use after free in Visuals

Are we really leading this section with an advisory this month? Yes. This Chrome bug was technically patched Friday (one day after an anonymous researcher reported it to Google), and it’s mentioned in Microsoft’s Patch Tuesday release simply to assure Edge users that the latest version addresses this high-severity issue. That said, Edge – and all browsers using Chromium OSS – need to patch immediately, as this one was found in the wild. Go.

CVE-2024-30040 – Windows MSHTML Platform Security Feature Bypass Vulnerability
CVE-2024-30051 — Windows DWM Core Library Elevation of Privilege Vulnerability

Two additional issues have been detected under exploit in the wild. The MSHTML issue has a base CVSS value of 8.8; the bug bypasses a feature in Microsoft 365 called OLE Auto-Activation Block, which allows admins to prevent abuse of OLE/COM. An attacker would abuse this bug by sending the targeted user a maliciously crafted file and then convincing them, to quote the bulletin, “to manipulate the specially crafted file, but not necessarily click or open the malicious file.” The DWM Core Library issue has a lower 7.8 base CVSS – and shares the stage with three other fixes addressing that component – but the list of credited finders is various and startling, including researchers from Kaspersky, Google Threat Analysis Group, Google Mandiant, and DBAPPSecurity WeBin Lab.

CVE-2024-30050 – Windows Mark of the Web Security Feature Bypass Vulnerability

April showers may be over, but the steady pitter-pat of Mark of the Web issues continues. This one’s Moderate in impact and limited in scope – a successful attack would lead to limited losses of integrity and availability of security features that rely on MotW, including Protected Mode in Office. Still, Microsoft assesses this one to be more likely to be exploited within the next 30 days, and the uses of a vulnerability like this in a chained attack should be kept in mind. Sophos has developed Intercept X/Endpoint IPS and XGS Firewall protections against this issue, as covered in the table below.

CVE-2024-30044 – Microsoft SharePoint Server Remote Code Execution Vulnerability

The month’s sole Critical-severity vulnerability affects SharePoint and is believed by Microsoft to be more likely to see exploitation in the next 30 days. Once again, Sophos has developed Intercept X/Endpoint IPS and XGS Firewall protections against this issue, as covered in the table below.

Figure 3: RCE issues continue to outpace all other types of vulnerability in 2024

Sophos protections

As you can every month, if you don’t want to wait for your system to pull down Microsoft’s updates itself, you can download them manually from the Windows Update Catalog website. Run the winver.exe tool to determine which build of Windows 10 or 11 you’re running, then download the Cumulative Update package for your specific system’s architecture and build number.

Appendix A: Vulnerability Impact and Severity

This is a list of May patches sorted by impact, then sub-sorted by severity. Each list is further arranged by CVE.

Remote Code Execution (25 CVEs)

Elevation of Privilege (17 CVEs)

Information Disclosure (7 CVEs)

Spoofing (4 CVEs)

Denial of Service (3 CVEs)

Security Feature Bypass (2 CVEs)

Tampering (1 CVE)

Appendix B: Exploitability

This is a list of the May CVEs already under exploit in the wild, and those judged by Microsoft to be more likely to be exploited in the wild within the first 30 days post-release. The list is arranged by CVE.

 Appendix C: Products Affected

This is a list of May’s patches sorted by product family, then sub-sorted by severity. Each list is further arranged by CVE. Patches that are shared among multiple product families are listed multiple times, once for each product family.

Windows (48 CVEs)

Dynamics 365 (2 CVEs)

SharePoint (2 CVEs)

Visual Studio (2* CVEs)

* In addition, this release includes information on two GitHub-issued advisories affecting Visual Studio; please see Appendix D for details.

.NET (1 CVE)

365 Apps for Enterprise (1 CVE)

Azure (1 CVE)

Bing Search for iOS (1 CVE)

Intune (1 CVE)

Office (1 CVE)

Power BI (1 CVE)

Appendix D: Advisories and Other Products

This is a list of advisories and information on other relevant CVEs in the May Microsoft release, sorted by product.

Relevant to Edge / Chromium (6 CVEs)

Relevant to Visual Studio (non-Microsoft CVE issuer) (2 CVEs)

Relevant to Adobe (non-Microsoft release) (4 CVEs)