Microsoft Drops December Patch Tuesday: 57 Bugs, 3 Zero‑Days, and a Whole Lot of RCE
Microsoft just shipped its latest Patch Tuesday bundle, fixing 57 vulnerabilities, including three actively exploited zero‑days and a pile of remote code execution flaws across Windows, Office, and developer tooling.[5] If you run Windows anywhere from your gaming rig to your prod servers, this one is not optional — it’s the kind of patch train you either get on or get run over by.[5]
According to Microsoft’s December security update, the company fixed 57 CVEs spanning Windows, Office, .NET, Azure components, and multiple server roles, with several rated “Critical” due to remote code execution impact.[5] Three zero‑days are listed as under active exploitation in the wild, including a Windows vulnerability that allows attackers to gain code execution or elevate privileges on fully patched systems prior to this update.[5]
The update follows Microsoft’s now-standard AI‑heavy security posture, but this is still classic exploit territory: weaponized documents, network‑exposed services, and scenarios where a single unpatched box becomes your new internal red‑team HQ.[5] For organizations with mixed fleets (on‑prem AD, RDS, Office, random legacy app servers), the blast radius of skipping this month is… non‑trivial.[5]
What actually shipped
Here’s the high‑impact stuff developers and sysadmins should care about:
- Total fixed: 57 CVEs across the stack, including multiple remote code execution and privilege escalation bugs.[5]
- Zero‑days: 3 vulnerabilities are flagged as exploited in the wild before a patch was available.[5]
- Scope: Core Windows OS, server components, Office, and related Microsoft software all receive updates in this batch.[5]
- Severity: Several bugs allow code execution with minimal user interaction (e.g., opening a document, hitting a malicious URL, or processing crafted input).[5]
SecurityWeek notes that Microsoft is still in “elevated threat” mode and continues to lean on AI‑driven detection and operational security changes around its security org.[4][5] That’s nice, but for defenders, what matters today is getting these specific binaries replaced before the exploit kits adopt them as standard payloads.
Why you, as a developer or power user, should care
If you build or run anything on Windows — local dev boxes, CI agents, self‑hosted runners, game rigs you occasionally RDP into, or that one forgotten “temp” VM still running a critical job — these are your real problems:
- Attack chains love unpatched dev boxes. Developer machines usually have powerful creds, SSH keys, cloud tokens, and admin tools. A zero‑day that pops a dev laptop is a cloud breach in two hops.[5]
- Prod outages via forced patching. If you don’t schedule this, you’ll eventually be forced to patch in the middle of an incident, when everything is on fire and nobody tested anything.[5]
- Compliance and audit. If you’re under SOC 2/ISO/PCI/etc., “we were 30 days behind Patch Tuesday” is not a line you want to say out loud.[5]
- Supply chain risk. Your app is only as secure as the images and runners you build it on; base Windows images lagging behind Patch Tuesday are soft targets.[5]
In short: if it runs Windows and touches code, credentials, or production, it needs this month’s patches — fast.
How to actually roll this out without wrecking your day
Here’s a minimal, sane workflow for anyone running Windows in a semi‑serious environment:
- Patch a small canary set first (one dev box, one test server, one non‑critical service).
- Smoke test core workflows (builds, deployments, logins, Office docs, VPN, etc.).
- Roll out in waves by environment: dev → test → staging → prod.
- Lock in deadlines: workstations within a few days, internet‑facing servers ASAP.
On individual or lab machines, you can also go direct via Windows Update or script it.
Quick technical example: scripting the patch rollout
If you’re the “just give me the command” type, here’s a PowerShell snippet you can run (as admin) on Windows 10/11 or Server to pull and apply updates, then reboot automatically:
# Install PSWindowsUpdate module if needed
Install-PackageProvider -Name NuGet -MinimumVersion 2.8.5.201 -Force
Install-Module -Name PSWindowsUpdate -Force
# Import the module
Import-Module PSWindowsUpdate
# List available Microsoft updates
Get-WindowsUpdate -MicrosoftUpdate
# Install all available updates and auto-reboot if required
Install-WindowsUpdate -MicrosoftUpdate -AcceptAll -AutoReboot
In larger environments, you’d obviously wire this into WSUS, Intune, SCCM, or your existing RMM, but this is enough to quickly close the gap on critical boxes that you control directly.
The blunt take
Every Patch Tuesday is not worth a blog post. This one is.
Three exploited zero‑days plus a big stack of RCEs is exactly the sort of thing that quietly turns into “how did they get domain admin?” six weeks later.[5] If you’re the person in the room who understands code, infrastructure, or security even a little more than everyone else, this is one of those times you raise your hand and say: “We’re patching this week. No, really.”
