Microsoft's December Patch Tuesday: 72 Vulnerabilities Addressed, Urgent Fixes Needed

If you were dreaming of wrapping up work early for the holidays, Microsoft has different plans for you. Its December Patch Tuesday is here, and it packs a punch with a hefty 72 new vulnerabilities patched in Windows and other Microsoft products. Among these fixes, an actively-exploited zero-day vulnerability stands out, affecting both server and desktop systems. Administrators and IT personnel have their marching orders: prioritize these updates now!
Let’s unpack this loaded Patch Tuesday, determine what's urgent, and explore the broader implications for Windows users, security professionals, and enterprises in general.

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The Vulnerability Rundown: 77 Patch Reasons to Not Skip Updates​

Microsoft's December updates fix 72 vulnerabilities and revise five previously reported issues, totaling 77 Common Vulnerabilities and Exposures (CVEs) patched. Here's how they break down by severity:

• 17 Critical vulnerabilities
• 54 Important vulnerabilities
• 1 Moderate vulnerability

Over 70% of these CVEs affect the Windows operating system, but a few also hit Microsoft Office, SharePoint Server, Hyper-V, and even a quirky AI music-development tool from GitHub. Here's a closer look at the ones you cannot ignore:

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1. Windows Zero-Day Threats at Large (CVE-2024-49138)​

Severity Rating: Important
CVSS Score: 7.8
Microsoft confirmed that a vulnerability in the Windows Common Log File System (CLFS) Driver—an elevation-of-privilege flaw—has been weaponized in the wild. If exploited, attackers could escalate privileges to gain system-level access, aka complete control of a device. All supported Windows Server and client platforms are vulnerable.

How This Works​

CLFS is deeply embedded in logging mechanisms within Windows OS, ensuring applications and services log their activity. Exploiting this zero-day requires a two-fold approach:

• The attacker must gain local access to the target system or trick the user into executing malicious code, for example, via a tampered email attachment or infected file download.
• Once inside, the attacker gains a foothold from standard user privileges to full-blown admin-level control.

The lesson here? Patch your Windows systems before someone exploits this. While Microsoft rated this vulnerability "Important," security experts recommend treating it as Critical.

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2. The Magnitude of LDAP Remote Code Execution (CVE-2024-49112)​

Severity Rating: Critical
CVSS Score: 9.8
Windows Server and desktop platforms didn’t get off easy—this Windows Lightweight Directory Access Protocol (LDAP) vulnerability has the highest severity score this month. Attackers exploiting this can send specially crafted LDAP requests to a vulnerable system, potentially leading to data theft, unauthorized file modification, or system crashes.

LDAP in a Nutshell​

LDAP is like the backbone of Active Directory (AD), the service responsible for authenticating and authorizing user accounts, groups, and devices throughout a Windows environment.
If an attacker intercepts poorly-secured LDAP traffic—especially if the domain controller (an Active Directory server) is exposed to the internet—it’s bad news for your IT infrastructure.
Mitigations:

• Disable all outbound/inbound Remote Procedure Calls (RPC) from untrusted networks to domain controllers.
• Better yet, ensure domain controllers do not directly connect to the internet. However, as with CVE-2024-49138, apply the patch immediately for comprehensive protection.

This is one bug cybercriminals would love to exploit, as remote execution opens a direct channel to wreck havoc at scale.

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3. Muzic AI Project and the Expanding Threat of AI Vulnerabilities​

Severity Rating: Important
CVSS Score: Not disclosed in detail.
CVE-2024-49063 exposes a vulnerability in the Muzic AI project, a GitHub open-source program used for AI-driven music composition and analysis. Attackers could potentially push malicious payloads and run unwanted code via an unpatched system.

Larger Implications​

AI and machine learning platforms are rapidly infiltrating enterprise workflows. With this adoption surge comes a growing attack surface. Vulnerabilities in open-source AI projects like Muzic are canaries in the coal mine for enterprises relying on new technologies. As organizations race to harness AI, IT admins mustn’t forget to audit these implementations and apply remediation strategies, patches, and robust permissions.

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4. Exchange Servers—The Saga Continues​

November wasn’t kind to Exchange Server administrators, and the headaches have carried over to December. After pulling back buggy updates that crippled email transport rules, introduced time zone errors, and caused attachments to misbehave, Microsoft postponed Exchange Server Cumulative Update 15 (CU15) to January 2025.
Why Should You Care?
Microsoft isn't prioritizing on-premises Exchange anymore—fact. Delayed patches and inconsistent updates signal that Exchange Server admins should begin migrating to Exchange Online or exploring other alternatives.
"Ignoring these trends keeps your IT infrastructure in the past," said a leading security advocate. Legacy Exchange Server deployments are security liabilities unless meticulously maintained.

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New Kid Alert: Windows 11 Hotpatching—A Game-Changer?​

Microsoft announced the introduction of hotpatching for Windows 11 Enterprise (24H2)—a feature earlier restricted to Windows Server. The concept here is exciting: reduce disruptive reboots through on-the-fly patch applications for security fixes.
Here’s how it works:

1. With hotpatching, Windows systems will only reboot after the first monthly cumulative update installation in a quarter.
2. Subsequent updates—for two months—get applied without needing a restart.

The Catch?
Only enterprise users running subscriptions like Windows E3/E5 or Windows 365 Enterprise are eligible. Additionally, Intune and Windows Autopatch are required for deployment.
This initiative could save millions of lost productivity hours if further streamlined into consumer editions in years to come.

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The Increasing Case for Fast Patching in 2024 and Beyond​

Industry experts are ringing the alarm bells: zero-day vulnerabilities and freshly-exploited CVEs are emerging faster than ever. AI and machine learning tools—helpful to security researchers—are speeding up exploit discovery capabilities for both good guys and bad actors. This arms race means enterprises need to:

• Move Faster: Patch immediately after every Patch Tuesday.
• Adopt Automated Tools: Embrace Windows Autopatch and similar platforms for quicker rollouts.
• Take Defense-in-Depth Seriously: Backup critical systems, enforce strong access policies, and avoid exposing mission-critical services online.

Chris Goettl, a security expert, warns that “zero-day counts are destined to rise, so the urgency for responses will only intensify.”

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Final Takeaway​

With highlights like a Windows zero-day (CVE-2024-49138), a critical LDAP exploit (CVE-2024-49112), and Exchange Server woes, December’s Patch Tuesday is redefining what a busy holiday month looks like for Windows admins. Staying on top of these patches is no longer optional—it’s survival.
Between hotpatching for Windows 11 and Microsoft’s sluggish attention to Exchange Server, the direction is clear—cloud and security automation are the future. With 2024 in full swing, brace yourselves for even more attacks, vulnerabilities, and rapid security revelations. Don’t hit snooze on Patch Tuesdays anymore.

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Source: TechTarget December Patch Tuesday shuts down Windows zero-day