Welcome to the first Patch Tuesday of the year; let’s find out what new surprises and challenges await. This year with 159 vulnerabilities, eight of them being zero-days. This time, three of the zero-days are being actively exploited.
After an initial discussion about this month’s updates, we’ll offer our advice for devising a plan to handle patch management in a hybrid work environment. You can also register for our free Patch Tuesday webinar and listen to our experts break down Patch Tuesday updates in detail.
What is Patch Tuesday?
Patch Tuesday falls on the second Tuesday of every month. On this day, Microsoft releases security and non-security updates for its operating system and other related applications. Since Microsoft has upheld this process of releasing updates in a periodic manner, IT admins expect these updates and have time to gear up for them.
Why is Patch Tuesday important?
Important security updates and patches to fix critical bugs or vulnerabilities are released on Patch Tuesday. Usually, zero-day vulnerabilities are also fixed during Patch Tuesday unless the vulnerability is critical and highly exploited, in which case an out-of-band security update is released to address that particular vulnerability.
January 2025 Patch Tuesday
Security updates lineup
Here is a breakdown of the vulnerabilities fixed this month:
CVE IDs: 159
Republished CVE IDs: 2 (more details on this below)
Security updates were released for the following products, features, and roles:
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.NET
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.NET and Visual Studio
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.NET, .NET Framework, Visual Studio
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Active Directory Domain Services
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Active Directory Federation Services
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Azure Marketplace SaaS Resources
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BranchCache
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Internet Explorer
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IP Helper
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Line Printer Daemon Service (LPD)
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Microsoft AutoUpdate (MAU)
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Microsoft Azure Gateway Manager
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Microsoft Brokering File System
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Microsoft Digest Authentication
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Microsoft Graphics Component
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Microsoft Office
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Microsoft Office Access
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Microsoft Office Excel
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Microsoft Office OneNote
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Microsoft Office Outlook
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Microsoft Office Outlook for Mac
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Microsoft Office SharePoint
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Microsoft Office Visio
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Microsoft Office Word
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Microsoft Purview
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Microsoft Windows Search Component
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Power Automate
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Reliable Multicast Transport Driver (RMCAST)
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Visual Studio
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Windows BitLocker
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Windows Boot Loader
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Windows Boot Manager
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Windows Client-Side Caching (CSC) Service
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Windows Cloud Files Mini Filter Driver
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Windows COM
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Windows Connected Devices Platform Service
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Windows Cryptographic Services
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Windows Digital Media
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Windows Direct Show
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Windows DWM Core Library
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Windows Event Tracing
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Windows Geolocation Service
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Windows Hello
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Windows Hyper-V NT Kernel Integration VSP
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Windows Installer
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Windows Kerberos
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Windows Kernel Memory
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Windows MapUrlToZone
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Windows Message Queuing
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Windows NTLM
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Windows OLE
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Windows PrintWorkflowUserSvc
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Windows Recovery Environment Agent
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Windows Remote Desktop Services
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Windows Secure Boot
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Windows Security Account Manager
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Windows Smart Card
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Windows SmartScreen
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Windows SPNEGO Extended Negotiation
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Windows Telephony Service
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Windows Themes
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Windows UPnP Device Host
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Windows Virtual Trusted Platform Module
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Windows Virtualization-Based Security (VBS) Enclave
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Windows Web Threat Defense User Service
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Windows Win32K – GRFX
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Windows WLAN Auto Config Service
Learn more in the MSRC’s release notes.
Details of the zero-day vulnerabilities
Vulnerable component: Windows Hyper-V NT Kernel Integration VSP
Impact: Elevation of privilege
CVSS 3.1: 7.8
These vulnerabilities allow attackers to execute arbitrary code with elevated privileges on affected systems. Per Microsoft, “An attacker who successfully exploited this vulnerability could gain SYSTEM privileges.”
While these vulnerabilities are being actively exploited, these haven’t been publicly disclosed before.
- CVE-2025-21186, CVE-2025-21366, CVE-2025-21395
Vulnerable component: Microsoft Access
Impact: Remote Code Execution
CVSS 3.1: 7.8
As of now, the vulnerabilities have been publicly disclosed, but there have been no recorded instances of exploitation. The updates released potentially block certain types of malicious extensions from being sent via email. The extensions are:
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accdb
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accde
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accdw
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accdt
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accda
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accdr
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accdu
Vulnerable component: Windows Themes
Impact: Spoofing
CVSS 3.1: 6.5
Microsoft states, “An attacker would have to convince the user to load a malicious file onto a vulnerable system, typically by way of an enticement in an Email or Instant Messenger message, and then convince the user to manipulate the specially crafted file, but not necessarily click or open the malicious file.”
As for the mitigation, Windows systems that have NTLM disabled in them are not affected by the vulnerability, while the other systems need to block the NTLM hash by applying an existing Group Policy, for which details can be found here.
Vulnerable component: Windows App Package Installer
Impact: Elevation of Privilege
CVSS 3.1: 7.8
This vulnerability has also been publicly disclosed, yet no instances of active exploitation have been noted. Microsoft has stated that the attackers can gain SYSTEM privileges by exploiting the vulnerability.
Republished CVE IDs
Besides the vulnerabilities fixed in this month’s Patch Tuesday, Microsoft has also republished two CVE IDs. These are as follows:
Some third-party vendors such as Adobe, Cisco, SAP, Fortinet, and Ivanti have also released updates this January.
Most organizations have opted to embrace remote work even after they have been cleared to return to the office. This decision poses various challenges to IT admins, especially in terms of managing and securing distributed endpoints.
Here are a few pointers to simplify the process of remote patching:
- Disable automatic updates because one faulty patch could bring down the whole system. IT admins can educate end users on how to disable automatic updates on their machines. Patch Manager Plus and Endpoint Central also have a dedicated patch, 105427, that can be deployed to endpoints to ensure that automatic updates are disabled.
- Create a restore point—a backup or image that captures the state of the machines—before deploying big updates like those from Patch Tuesday.
- Establish a patching schedule and keep end users informed about it. It is recommended to set up a time for deploying patches and rebooting systems. Let end users know what needs to be done on their end for trouble-free patching.
- Test the patches on a pilot group of systems before deploying them to the production environment. This will ensure that the patches do not interfere with the workings of other applications.
- Since many users are working from home, they all might be working different hours; in this case, you can allow end users to skip deployment and scheduled reboots. This will give them the liberty to install updates at their convenience and avoid disrupting their work. Our patch management products come with options for user-defined deployment and reboot.
- Most organizations are deploying patches using a VPN. To stop patch tasks from eating up your VPN bandwidth, install Critical patches and security updates first. You might want to hold off on deploying feature packs and cumulative updates since they are bulky updates and consume a lot of bandwidth.
- Schedule the non-security updates and security updates that are not rated Critical to be deployed after Patch Tuesday, such as during the third or fourth week of the month. You can also choose to decline certain updates if you feel they are not required in your environment.
- Run patch reports to get a detailed view of the health status of your endpoints.
For machines belonging to users returning to the office after working remotely, check if they are compliant with your security policies. If not, quarantine them. Install the latest updates and feature packs before deeming your back-to-office machines fit for production. Take inventory of and remove apps that are now obsolete for your back-to-office machines, like remote collaboration software.
With Endpoint Central, Patch Manager Plus, or Vulnerability Manager Plus, you can completely automate the entire process of patch management, from testing patches to deploying them. You can also tailor patch tasks according to your current needs. For a hands-on experience with either of these products, try a free, 30-day trial and keep thousands of applications patched and secure.
Want to learn more about Patch Tuesday updates? Join our experts as they break down this month’s Patch Tuesday updates and offer in-depth analysis. You can also ask our experts questions and get answers to all your Patch Tuesday questions. Register for our free Patch Tuesday webinar.
Ready, get set, patch!
