Ethical Hacking News

Microsoft's December 2025 Patch Tuesday Brings a Slew of Security Patches to Fix Over 56 Vulnerabilities

Microsoft has released its latest Patch Tuesday update, fixing over 56 vulnerabilities in its Windows operating systems and supported software, including one zero-day bug that is already being exploited by threat actors. The patch batch includes fixes for critical bugs in Microsoft Office and Outlook as well as non-critical privilege escalation bugs. Cybersecurity experts urge users to apply the patches as soon as possible to prevent potential security breaches.

Microsoft has released a new patch batch that fixes at least 56 security flaws, including one zero-day bug.

A zero-day vulnerability (CVE-2025-62221) affects Windows 10 and later editions, specifically the "Windows Cloud Files Mini Filter Driver" component.

The mini filter is integral to cloud applications such as OneDrive, Google Drive, and iCloud, making it a significant threat due to its widespread use.

55 other vulnerabilities were patched in addition to the zero-day bug, including three critical-rated bugs involving Microsoft Office and Outlook.

The most likely exploited vulnerabilities from this month's patch batch are non-critical privilege escalation bugs.

A remote code execution flaw (CVE-2025-64671) was also patched in the Github Copilot Plugin for Jetbrains AI-based coding assistant.

CVE-2025-54100 is a remote code execution bug in Windows Powershell on Windows Server 2008 and later that allows an unauthenticated attacker to run code in the security context of the user.

December 9, 2025 - In a move to bolster the security posture of its Windows operating systems and supported software, Microsoft has released a slew of security patches in its latest Patch Tuesday update. According to the company's announcement, the patch batch fixes at least 56 security flaws, including one zero-day bug that is already being exploited by threat actors.

The zero-day vulnerability, identified as CVE-2025-62221, affects Windows 10 and later editions, specifically the "Windows Cloud Files Mini Filter Driver" component. This driver is integral to cloud applications such as OneDrive, Google Drive, and iCloud, and remains a core Windows component even if none of these apps were installed. According to Adam Barnett, lead software engineer at Rapid7, this vulnerability poses a significant threat due to its widespread use.

"This is particularly concerning, as the mini filter is integral to services like OneDrive, Google Drive, and iCloud, and remains a core Windows component, even if none of those apps were installed," said Barnett. "The fact that it's being exploited by threat actors makes it a serious vulnerability that should be patched as soon as possible."

In addition to the zero-day bug, Microsoft has also patched 55 other vulnerabilities in its latest patch batch. Of these, three have earned the company's most-dire "critical" rating: both CVE-2025-62554 and CVE-2025-62557 involve Microsoft Office, and both can be exploited merely by viewing a booby-trapped email message in the Preview Pane. Another critical bug, CVE-2025-62562, involves Microsoft Outlook, although Redmond says the Preview Pane is not an attack vector with this one.

However, according to Microsoft, the vulnerabilities most likely to be exploited from this month's patch batch are other (non-critical) privilege escalation bugs. These include CVE-2025-62458 - Win32k, CVE-2025-62470 - Windows Common Log File System Driver, CVE-2025-62472 - Windows Remote Access Connection Manager, CVE-2025-59516 - Windows Storage VSP Driver, and CVE-2025-59517 - Windows Storage VSP Driver.

Kev Breen, senior director of threat research at Immersive, said that privilege escalation flaws are observed in almost every incident involving host compromises. "We don't know why Microsoft has marked these specifically as more likely, but the majority of these components have historically been exploited in the wild or have enough technical detail on previous CVEs that it would be easier for threat actors to weaponize these," Breen said.

One of the more interesting vulnerabilities patched this month is CVE-2025-64671, a remote code execution flaw in the Github Copilot Plugin for Jetbrains AI-based coding assistant. This flaw would allow attackers to execute arbitrary code by tricking the large language model (LLM) into running commands that bypass the guardrails and add malicious instructions in the user's "auto-approve" settings.

CVE-2025-64671 is part of a broader, more systemic security crisis that security researcher Ari Marzuk has branded IDEsaster (IDE stands for “integrated development environment”). This crisis encompasses more than 30 separate vulnerabilities reported in nearly a dozen market-leading AI coding platforms, including Cursor, Windsurf, Gemini CLI, and Claude Code.

The other publicly-disclosed vulnerability patched today is CVE-2025-54100, a remote code execution bug in Windows Powershell on Windows Server 2008 and later that allows an unauthenticated attacker to run code in the security context of the user.

For anyone seeking a more granular breakdown of the security updates Microsoft pushed today, check out the roundup at the SANS Internet Storm Center. As always, please leave a note in the comments if you experience problems applying any of this month's Windows patches.

Related Information:

https://www.ethicalhackingnews.com/articles/Microsofts-December-2025-Patch-Tuesday-Brings-a-Slew-of-Security-Patches-to-Fix-Over-56-Vulnerabilities-ehn.shtml

https://krebsonsecurity.com/2025/12/microsoft-patch-tuesday-december-2025-edition/

https://nvd.nist.gov/vuln/detail/CVE-2025-62221

https://www.cvedetails.com/cve/CVE-2025-62221/

https://nvd.nist.gov/vuln/detail/CVE-2025-62554

https://www.cvedetails.com/cve/CVE-2025-62554/

https://nvd.nist.gov/vuln/detail/CVE-2025-62557

https://www.cvedetails.com/cve/CVE-2025-62557/

https://nvd.nist.gov/vuln/detail/CVE-2025-62562

https://www.cvedetails.com/cve/CVE-2025-62562/

https://nvd.nist.gov/vuln/detail/CVE-2025-62458

https://www.cvedetails.com/cve/CVE-2025-62458/