Microsoft September 2024 Patch Tuesday: What You Need to Know

Microsoft’s September 2024 Patch Tuesday update has just arrived, addressing 79 vulnerabilities across a range of services and applications, including four zero-day exploits currently active in the wild. These vulnerabilities pose immediate risks to users, so patching them should be a top priority for all IT professionals.

Key Zero-Day Vulnerabilities

  1. CVE-2024-38014: This critical Windows Installer vulnerability allows attackers to elevate their privileges without user interaction. It can be particularly dangerous when combined with other flaws that provide access to a system.
  2. CVE-2024-38226: A security bypass flaw in Microsoft Publisher that allows attackers to exploit Office macro policies. This zero-day is being actively exploited to run malicious code.
  3. CVE-2024-38217: A vulnerability in Windows’ Mark of the Web (MoTW) feature, which attackers can exploit to bypass key security checks like SmartScreen. This leaves systems vulnerable to malicious files downloaded from the web.
  4. CVE-2024-43461: A spoofing flaw in Windows MSHTML that allows attackers to impersonate legitimate services and execute malicious code.

Why It Matters

The nature of these vulnerabilities, particularly the zero-days, makes them critical to address immediately. The affected software spans many essential Microsoft products, including Office, Azure, and core Windows services like Installer. Ignoring these patches leaves systems at risk for privilege escalation attacks, where attackers gain elevated access, or for remote code execution, which can lead to a full system compromise.

Besides the four zero-days, the remaining 75 vulnerabilities are just as concerning, covering areas like SharePoint, Power Automate, and Windows kernel. The potential for exploitation across these varied systems shows how diverse and far-reaching the threat landscape is, especially for enterprises reliant on Microsoft technologies.

What Is Exploit Wednesday?

The day after Microsoft’s Patch Tuesday—often dubbed Exploit Wednesday—is infamous in the cybersecurity world. While Patch Tuesday is when the fixes for vulnerabilities are released, Exploit Wednesday refers to the day when attackers often begin targeting the newly disclosed vulnerabilities, especially those that haven’t been patched yet. As soon as vulnerabilities are made public, malicious actors will rush to develop exploits, knowing that many organisations won’t have applied patches immediately.

For the layperson, Exploit Wednesday can be thought of as a race between attackers and defenders. On one side, hackers work to exploit the vulnerabilities revealed the day before, while on the other, IT teams scramble to apply the patches to prevent these exploits from being successful. If you haven’t patched your system by Wednesday, you’re essentially rolling the dice and hoping that your organisation isn’t targeted.

This race between attackers and IT administrators is why Patch Tuesday isn’t just an event for the security industry—it’s crucial for any business or individual using Microsoft products. By understanding and applying these updates quickly, you reduce your risk of becoming the next victim of cybercrime.

What You Should Do

  • Deploy Patches Immediately: These vulnerabilities, especially the zero-days, need to be addressed urgently. Ensure that all updates are applied across your network.
  • Prioritise Critical Systems: Focus on systems that are most at risk, particularly those utilising SharePoint, Windows Installer, and Microsoft Office, as these have been directly affected by zero-day vulnerabilities.
  • Monitor for Exploit Attempts: Even after patches are applied, monitoring systems for any signs of attack or unusual behaviour is crucial. Threat actors may have already exploited the vulnerabilities before patches were deployed.

By acting quickly and proactively applying these patches, you’ll protect your organisation from being compromised by these vulnerabilities. Microsoft has provided the necessary tools—now it’s up to businesses to ensure they’re used effectively.

For full details on the updates, refer to Microsoft’s official Patch Tuesday update notes​