Microsoft Issues Patches for 79 Flaws, Including 3 Actively Exploited Windows Flaws

September 11, 2024

Microsoft on Tuesday disclosed that three new security flaws impacting the Windows platform have come under active exploitation as part of its Patch Tuesday update for September 2024.

The monthly security release addresses a total of 79 vulnerabilities, of which seven are rated Critical, 71 are rated Important, and one is rated Moderate in severity. This is aside from 26 flaws that the tech giant resolved in its Chromium-based Edge browser since last month's Patch Tuesday release.

The three vulnerabilities that have been weaponized in a malicious context are listed below, alongside a bug that Microsoft is treating as exploited -

CVE-2024-38014 (CVSS score: 7.8) - Windows Installer Elevation of Privilege Vulnerability
CVE-2024-38217 (CVSS score: 5.4) - Windows Mark-of-the-Web (MotW) Security Feature Bypass Vulnerability
CVE-2024-38226 (CVSS score: 7.3) - Microsoft Publisher Security Feature Bypass Vulnerability
CVE-2024-43491 (CVSS score: 9.8) - Microsoft Windows Update Remote Code Execution Vulnerability

"Exploitation of both CVE-2024-38226 and CVE-2024-38217 can lead to the bypass of important security features that block Microsoft Office macros from running," Satnam Narang, senior staff research engineer at Tenable, said in a statement.

"In both cases, the target needs to be convinced to open a specially crafted file from an attacker-controlled server. Where they differ is that an attacker would need to be authenticated to the system and have local access to it to exploit CVE-2024-38226."

As disclosed by Elastic Security Labs last month, CVE-2024-38217 – also referred to as LNK Stomping – is said to have been abused in the wild as far back as February 2018.

CVE-2024-43491, on the other hand, is notable for the fact that it's similar to the downgrade attack that cybersecurity company SafeBreach detailed early last month.

"Microsoft is aware of a vulnerability in Servicing Stack that has rolled back the fixes for some vulnerabilities affecting Optional Components on Windows 10, version 1507 (initial version released July 2015)," Redmond noted.

"This means that an attacker could exploit these previously mitigated vulnerabilities on Windows 10, version 1507 (Windows 10 Enterprise 2015 LTSB and Windows 10 IoT Enterprise 2015 LTSB) systems that have installed the Windows security update released on March 12, 2024 — KB5035858 (OS Build 10240.20526) or other updates released until August 2024."

The Windows maker further said it can be resolved by installing the September 2024 Servicing stack update (SSU KB5043936) and the September 2024 Windows security update (KB5043083), in that order.

It's also worth pointing out that Microsoft's "Exploitation Detected" assessment for CVE-2024-43491 stems from the rollback of fixes that addressed vulnerabilities impacting some Optional Components for Windows 10 (version 1507) that have been previously exploited.

"No exploitation of CVE-2024-43491 itself has been detected," the company said. "In addition, the Windows product team at Microsoft discovered this issue, and we have seen no evidence that it is publicly known."

Software Patches from Other Vendors

In addition to Microsoft, security updates have also been released by other vendors over the past few weeks to rectify several vulnerabilities, including —