CVE-2025-62221
published 2025-12-09CVE-2025-62221: Use after free in Windows Cloud Files Mini Filter Driver allows an authorized attacker to elevate privileges locally.
PriorityP184high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
KEVITW
CISA Known Exploited Vulnerabilitydue 2025-12-30
Exploited in the wild
EPSS
2.38%
82.0th percentile
Use after free in Windows Cloud Files Mini Filter Driver allows an authorized attacker to elevate privileges locally.
Affected
30 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| microsoft | windows_10_1809 | < 10.0.17763.8146 | 10.0.17763.8146 |
| microsoft | windows_10_21h2 | < 10.0.19044.6691 | 10.0.19044.6691 |
| microsoft | windows_10_22h2 | < 10.0.19045.6691 | 10.0.19045.6691 |
| microsoft | windows_10_version_1809 | >= 10.0.17763.0 < 10.0.17763.8146 | 10.0.17763.8146 |
| microsoft | windows_10_version_21h2 | >= 10.0.19044.0 < 10.0.19044.6691 | 10.0.19044.6691 |
| microsoft | windows_10_version_22h2 | >= 10.0.19045.0 < 10.0.19045.6691 | 10.0.19045.6691 |
| microsoft | windows_11_23h2 | < 10.0.22631.6345 | 10.0.22631.6345 |
| microsoft | windows_11_24h2 | < 10.0.26100.7392 | 10.0.26100.7392 |
| microsoft | windows_11_25h2 | < 10.0.26200.7392 | 10.0.26200.7392 |
| microsoft | windows_11_version_22h3 | >= 10.0.22631.0 < 10.0.22631.6345 | 10.0.22631.6345 |
| microsoft | windows_11_version_23h2 | >= 10.0.22631.0 < 10.0.22631.6345 | 10.0.22631.6345 |
| microsoft | windows_11_version_24h2 | >= 10.0.26100.0 < 10.0.26100.7462 | 10.0.26100.7462 |
| microsoft | windows_11_version_25h2 | >= 10.0.26200.0 < 10.0.26200.7462 | 10.0.26200.7462 |
| microsoft | windows_server_2019 | < 10.0.17763.8146 | 10.0.17763.8146 |
| microsoft | windows_server_2019 | >= 10.0.17763.0 < 10.0.17763.8146 | 10.0.17763.8146 |
| microsoft | windows_server_2022 | < 10.0.20348.4467 | 10.0.20348.4467 |
| microsoft | windows_server_2022 | >= 10.0.20348.0 < 10.0.20348.4529 | 10.0.20348.4529 |
| microsoft | windows_server_2022_23h2 | < 10.0.25398.2025 | 10.0.25398.2025 |
| microsoft | windows_server_2025 | < 10.0.26100.7392 | 10.0.26100.7392 |
| microsoft | windows_server_2025 | >= 10.0.26100.0 < 10.0.26100.7462 | 10.0.26100.7462 |
| msrc | windows_10_version_1809 | — | — |
| msrc | windows_10_version_21h2 | — | — |
| msrc | windows_10_version_22h2 | — | — |
| msrc | windows_11_version_23h2 | — | — |
| msrc | windows_11_version_24h2 | — | — |
Detection & IOCsextracted from sources · hover to see the quote
- →CVE-2025-62221 is a use-after-free in the Windows Cloud Files Mini Filter Driver (cldflt.sys) residing in the routine 'HsmOsBlockPlaceholderAccess'; exploitation requires only local access, low privileges, and no user interaction, resulting in SYSTEM-level privilege escalation. ↗
- →Exploitation has been confirmed in the wild (CISA KEV listed); monitor for low-privileged processes spawning SYSTEM-level child processes (e.g., cmd.exe running as SYSTEM) on Windows hosts with Cloud Files Mini Filter Driver active. ↗
- →A public PoC (MiniPlasma) exists that weaponizes the original Google Project Zero PoC for CVE-2020-17103 without modification to spawn a SYSTEM shell; treat any use of that PoC tooling as a high-confidence indicator of exploitation attempt. ↗
- →Patch reference: apply KB5071544, KB5071546, KB5072033, KB5072014, KB5071547, KB5071413, KB5071417, KB5071542 per Microsoft's December 2025 update guidance to remediate CVE-2025-62221. ↗
- ·Exploitation requires local access and low privileges (no remote vector); the attack surface is limited to authenticated local users on Windows systems with the Cloud Files Mini Filter Driver component active. ↗
- ·The MiniPlasma PoC does NOT work on the latest Windows 11 Insider Preview Canary builds, so detection/patching priority should focus on stable/production Windows 11 and earlier versions. ↗
CVSS provenance
nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
vulncheck7.8HIGH
cisa7.8HIGH
vendor_msrc7.8HIGH
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GHSA
GHSA-4xhr-vh2p-rpch: Use after free in Windows Cloud Files Mini Filter Driver allows an authorized attacker to elevate privileges locally
ghsa_unreviewed·2025-12-09
CVE-2025-62221 [HIGH] CWE-416 GHSA-4xhr-vh2p-rpch: Use after free in Windows Cloud Files Mini Filter Driver allows an authorized attacker to elevate privileges locally
Use after free in Windows Cloud Files Mini Filter Driver allows an authorized attacker to elevate privileges locally.
VulnCheck
Microsoft Windows Use After Free Vulnerability
vulncheck·2025·CVSS 7.8
CVE-2025-62221 [HIGH] CWE-416 Microsoft Windows Use After Free Vulnerability
Microsoft Windows Use After Free Vulnerability
Microsoft Windows Cloud Files Mini Filter Driver contains a use after free vulnerability that can allow an authorized attacker to elevate privileges locally.
Affected: Microsoft Windows
Required Action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Exploitation References: https://api.msrc.microsoft.com/cvrf/v3.0/cvrf/2025-Dec; https://docs.google.com/spreadsheets/d/1lkNJ0uQwbeC1ZTRrxdtuPLCIl7mlUreoKfSIgajnSyY/edit; https://msrc.microsoft.com/update-guide/en-US/advisory/CVE-2025-62221; https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json; https://www.recordedfuture.com/blog/december-2025-cve
CISA
Microsoft Windows Use After Free Vulnerability
cisa·2025-12-09·CVSS 7.8
CVE-2025-62221 [HIGH] CWE-416 Microsoft Windows Use After Free Vulnerability
Vulnerability: Microsoft Windows Use After Free Vulnerability
Affected: Microsoft Windows
Microsoft Windows Cloud Files Mini Filter Driver contains a use after free vulnerability that can allow an authorized attacker to elevate privileges locally.
Required Action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Notes: https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-62221 ; https://nvd.nist.gov/vuln/detail/CVE-2025-62221
Remediation Due Date: 2025-12-30
Microsoft
Windows Cloud Files Mini Filter Driver Elevation of Privilege Vulnerability
vendor_msrc·2025-12-09·CVSS 7.8
CVE-2025-62221 [HIGH] CWE-416 Windows Cloud Files Mini Filter Driver Elevation of Privilege Vulnerability
Windows Cloud Files Mini Filter Driver Elevation of Privilege Vulnerability
Description: Use after free in Windows Cloud Files Mini Filter Driver allows an authorized attacker to elevate privileges locally.
FAQ: What privileges could be gained by an attacker who successfully exploited this vulnerability?
An attacker who successfully exploited this vulnerability could gain SYSTEM privileges.
Windows Cloud Files Mini Filter Driver: Windows Cloud Files Mini Filter Driver
Microsoft: Microsoft
Customer Action Required: Yes
Impact: Elevation of Privilege
Exploit Status: Publicly Disclosed:No;Exploited:Yes;Latest Software Release:Exploitation Detected
Reference: https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5071544
Reference: https://support.microsoft.com/help/5071544
Ref
No detection rules found.
No public exploits indexed.
Hackernews
MiniPlasma Windows 0-Day Enables SYSTEM Privilege Escalation on Fully Patched Systems
blogs_hackernews·2026-05-18·CVSS 7.8
CVE-2020-17103 [HIGH] MiniPlasma Windows 0-Day Enables SYSTEM Privilege Escalation on Fully Patched Systems
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## MiniPlasma Windows 0-Day Enables SYSTEM Privilege Escalation on Fully Patched Systems
Chaotic Eclipse, the security researcher behind the recently disclosed Windows flaws, YellowKey and GreenPlasma , has released a proof-of-concept (PoC) for a Windows privilege escalation zero-day flaw that grants attackers SYSTEM privileges on fully patched Windows systems.
Codenamed MiniPlasma , the vulnerability impacts "cldflt.sys," which refers to the Windows Cloud Files Mini Filter Driver, and resides in a routine named "HsmOsBlockPlaceholderAccess." It was originally reported to Microsoft by Google Project Zero researcher James Forsha
Tenable
Microsoft’s December 2025 Patch Tuesday Addresses 56 CVEs (CVE-2025-62221)
blogs_tenable·2025-12-09·CVSS 7.8
[HIGH] Microsoft’s December 2025 Patch Tuesday Addresses 56 CVEs (CVE-2025-62221)
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Krebs
Microsoft Patch Tuesday, December 2025 Edition
blogs_krebs·2025-12-09·CVSS 7.8
[HIGH] Microsoft Patch Tuesday, December 2025 Edition
Microsoft today pushed updates to fix at least 56 security flaws in its Windows operating systems and supported software. This final Patch Tuesday of 2025 tackles one zero-day bug that is already being exploited, as well as two publicly disclosed vulnerabilities.
Despite releasing a lower-than-normal number of security updates these past few months, Microsoft patched a whopping 1,129 vulnerabilities in 2025, an 11.9% increase from 2024. According to Satnam Narang at Tenable, this year marks the second consecutive year that Microsoft patched over one thousand vulnerabilities, and the third time it has done so since its inception.
The zero-day flaw patched today is CVE-2025-62221, a privilege escalation vulnerability affecting Windows 10 and later editions. The weakness resides in a compon
Talos
Microsoft Patch Tuesday for December 2025 — Snort rules and prominent vulnerabilities
blogs_talos·2025-12-09·CVSS 8.8
[HIGH] Microsoft Patch Tuesday for December 2025 — Snort rules and prominent vulnerabilities
## Microsoft Patch Tuesday for December 2025 — Snort rules and prominent vulnerabilities
The Patch Tuesday for December of 2025 includes 57 vulnerabilities, including two that Microsoft marked as “critical.” The remaining vulnerabilities listed are classified as “important.” Microsoft assessed that exploitation of the two “critical” vulnerabilities is “less likely.”
CVE‑2025‑62562 is a Microsoft Outlook remote code execution vulnerability. Although it involves a use after free in Microsoft Office Outlook to allow an unauthorized attacker to execute code locally, an attacker would still need to send a malicious email and persuade the user to reply to it for the exploit to work.
CVE-2025-62553 , CVE-2025-62554 , CVE-2025-62556 and CVE-2025-62557 are Microsoft Office Remote Code Execution
Qualys
Microsoft and Adobe Patch Tuesday, December 2025 Security Update Review
blogs_qualys·2025-12-09
Microsoft and Adobe Patch Tuesday, December 2025 Security Update Review
## Table of Contents
Microsoft Patch Tuesday forDecember2025
Adobe Patches for December 2025
Zero-day Vulnerabilities Patched inDecemberPatch Tuesday Edition
Critical Severity Vulnerabilities Patched in DecemberPatch Tuesday Edition
Other Microsoft Vulnerability Highlights
Microsoft Release Summary
Discover and Prioritize Vulnerabilities inVulnerability Management, Detection & Response (VMDR)
Rapid Response with TruRisk Eliminate
Qualys Monthly Webinar Series
As the year winds down, Microsoft Patch Tuesday in December arrives with essential fixes and enhancements to close vulnerabilities and boost performance. Here’s a quick breakdown of what you need to know.
## Microsoft Patch Tuesday for December 2025
This month’s release addresses 72 vulnerabilities, including three critica
Talos
Microsoft Patch Tuesday for December 2025 — Snort rules and prominent vulnerabilities
blogs_talos·2025-12-09·CVSS 8.8
[HIGH] Microsoft Patch Tuesday for December 2025 — Snort rules and prominent vulnerabilities
The Patch Tuesday for December of 2025 includes 57 vulnerabilities, including two that Microsoft marked as “critical.” The remaining vulnerabilities listed are classified as “important.” Microsoft assessed that exploitation of the two “critical” vulnerabilities is “less likely.”
CVE‑2025‑62562 is a Microsoft Outlook remote code execution vulnerability. Although it involves a use after free in Microsoft Office Outlook to allow an unauthorized attacker to execute code locally, an attacker would still need to send a malicious email and persuade the user to reply to it for the exploit to work.
CVE-2025-62553, CVE-2025-62554, CVE-2025-62556 and CVE-2025-62557 are Microsoft Office Remote Code Execution Vulnerability. An attacker can access resources using incompatible type ('type confusion') o
Qualys
Microsoft and Adobe Patch Tuesday, December 2025 Security Update Review | Qualys
blogs_qualys·2025-12-09
Microsoft and Adobe Patch Tuesday, December 2025 Security Update Review | Qualys
#### Table of Contents
- Microsoft Patch Tuesday forDecember2025
- Adobe Patches for December 2025
- Zero-day Vulnerabilities Patched inDecemberPatch Tuesday Edition
- Critical Severity Vulnerabilities Patched in DecemberPatch Tuesday Edition
- Other Microsoft Vulnerability Highlights
- Microsoft Release Summary
- Discover and Prioritize Vulnerabilities inVulnerability Management, Detection & Response (VMDR)
- Rapid Response with TruRisk Eliminate
- Qualys Monthly Webinar Series
As the year winds down, Microsoft Patch Tuesday in December arrives with essential fixes and enhancements to close vulnerabilities and boost performance. Here’s a quick breakdown of what you need to know.
## Microsoft Patch Tuesday for December 2025
This month’s release addresses 72 vulnerabilities, including t
Bleepingcomputer
Microsoft December 2025 Patch Tuesday fixes 3 zero-days, 57 flaws
blogs_bleepingcomputer·2025-12-09·CVSS 7.8
[HIGH] Microsoft December 2025 Patch Tuesday fixes 3 zero-days, 57 flaws
## Microsoft December 2025 Patch Tuesday fixes 3 zero-days, 57 flaws
## Lawrence Abrams
28 Elevation of Privilege Vulnerabilities
19 Remote Code Execution Vulnerabilities
4 Information Disclosure Vulnerabilities
3 Denial of Service Vulnerabilities
2 Spoofing Vulnerabilities
When BleepingComputer reports on Patch Tuesday security updates, we only count those released by Microsoft today. Therefore, the number of flaws does not include Microsoft Edge (15 flaws) and Mariner vulnerabilities fixed earlier this month.
To learn more about the non-security updates released today, you can review our dedicated articles on the Windows 11 KB5072033 & KB5071417 cumulative updates .
If you're facing delays, blind spots, or prioritization issues with Patch Tuesday updates, our recent webinar with
Krebs
Microsoft Patch Tuesday, December 2025 Edition
blogs_krebs·2025-12-09·CVSS 7.8
[HIGH] Microsoft Patch Tuesday, December 2025 Edition
Microsoft today pushed updates to fix at least 56 security flaws in its Windows operating systems and supported software. This final Patch Tuesday of 2025 tackles one zero-day bug that is already being exploited, as well as two publicly disclosed vulnerabilities.
Despite releasing a lower-than-normal number of security updates these past few months, Microsoft patched a whopping 1,129 vulnerabilities in 2025, an 11.9% increase from 2024. According to Satnam Narang at Tenable , this year marks the second consecutive year that Microsoft patched over one thousand vulnerabilities, and the third time it has done so since its inception.
The zero-day flaw patched today is CVE-2025-62221 , a privilege escalation vulnerability affecting Windows 10 and later editions. The weakness resides in a comp
Qualys
Zero-Day Vulnerability Protection | Detect & Stop Threats | Qualys
blogs_qualys·2025-04-18
Zero-Day Vulnerability Protection | Detect & Stop Threats | Qualys
## Table of Contents
Why Zero-Day Vulnerabilities Demand a New Security Mindset
Understanding Zero-Day Vulnerabilities, Exploits, and Attacks
How Do Zero-Day Attacks Work?
The Zero-Day Lifecycle: From Discovery to Exploitation
Real-World Zero-Day Attacks and Their Impact
Why Zero-Day Vulnerabilities Are So Dangerous
Detecting Zero-Day Vulnerabilities
Challenges in Identifying Zero-Day Vulnerabilities
How Qualys Helps Organizations Manage Zero-Day Risk
Conclusion
Frequently Asked Questions (FAQs)
Executive Summary
Zero-day vulnerabilities pose a significant and growing risk as opportunistic attackers rapidly exploit unknown flaws before fixes are available. These threats can bypass traditional defenses, spread rapidly, and cause widespread disruption across organizations.
To r
Qualys
Zero-Day Vulnerability Protection | Detect & Stop Threats | Qualys
blogs_qualys·2025-04-18
Zero-Day Vulnerability Protection | Detect & Stop Threats | Qualys
#### Table of Contents
- Why Zero-Day Vulnerabilities Demand a New Security Mindset
- Understanding Zero-Day Vulnerabilities, Exploits, and Attacks
- How Do Zero-Day Attacks Work?
- The Zero-Day Lifecycle: From Discovery to Exploitation
- Real-World Zero-Day Attacks and Their Impact
- Why Zero-Day Vulnerabilities Are So Dangerous
- Detecting Zero-Day Vulnerabilities
- Challenges in Identifying Zero-Day Vulnerabilities
- How Qualys Helps Organizations Manage Zero-Day Risk
- Conclusion
- Frequently Asked Questions (FAQs)
Executive Summary
Zero-day vulnerabilities pose a significant and growing risk as opportunistic attackers rapidly exploit unknown flaws before fixes are available. These threats can bypass traditional defenses, spread rapidly, and cause widespread disruption across organi
Recorded Future
December 2025 CVE Landscape: 22 Critical Vulnerabilities Mark 120% Surge, React2Shell Dominates Threat Activity
blogs_recorded_future·CVSS 7.8
CVE-2025-55182 [HIGH] December 2025 CVE Landscape: 22 Critical Vulnerabilities Mark 120% Surge, React2Shell Dominates Threat Activity
# December 2025 CVE Landscape: 22 Critical Vulnerabilities Mark 120% Surge, React2Shell Dominates Threat Activity
December 2025 witnessed a dramatic 120% increase in high-impact vulnerabilities, with Recorded Future's Insikt Group® identifying 22 vulnerabilities requiring immediate remediation, up from 10 in November. The month was dominated by widespread exploitation of Meta's React Server Components flaw.
What security teams need to know:
- React2Shell pandemonium: CVE-2025-55182 triggered a global exploitation wave with multiple threat actors deploying diverse malware families
- China-nexus exploitation intensifies: Earth Lamia, Jackpot Panda, and UAT-9686 leveraged critical flaws for espionage operations
- Public exploits proliferate: Eleven of 22 vulnerabilities have proof-of-conce
Crowdstrike
December 2025 Patch Tuesday: Updates and Analysis
blogs_crowdstrike·CVSS 7.5
CVE-2026-20929 [HIGH] December 2025 Patch Tuesday: Updates and Analysis
How CrowdStrike is Accelerating Exposure Evaluation as Adversaries Gain Speed Apr 06, 2026
STARDUST CHOLLIMA Likely Compromises Axios npm Package Apr 01, 2026
Falcon for IT Supports Windows Secure Boot Certificate Lifecycle Management Apr 01, 2026
Detecting CVE-2026-20929: Kerberos Authentication Relay via CNAME Abuse Mar 31, 2026
How CrowdStrike is Accelerating Exposure Evaluation as Adversaries Gain Speed Apr 06, 2026
STARDUST CHOLLIMA Likely Compromises Axios npm Package Apr 01, 2026
Falcon for IT Supports Windows Secure Boot Certificate Lifecycle Management Apr 01, 2026
Detecting CVE-2026-20929: Kerberos Authentication Relay via CNAME Abuse Mar 31, 2026
Video Highlights the 4 Key Steps to Successful Incident Response Dec 02, 2019
Helping Non-Security Stakeholders Understand AT
Zscaler
Zscaler protects against 6 new vulnerabilities | 12-09-2025
blogs_zscaler·CVSS 7.8
[HIGH] Zscaler protects against 6 new vulnerabilities | 12-09-2025
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Wiz
CVE-2025-62221 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 7.8
CVE-2025-62221 [HIGH] CVE-2025-62221 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2025-62221 :
vulnerability analysis and mitigation
Use after free in Windows Cloud Files Mini Filter Driver allows an authorized attacker to elevate privileges locally.
Source : NVD
## 7.8
Score
Published December 9, 2025
Severity HIGH
CNA Score 7.8
Has Public Exploit Yes
Has CISA KEV Exploit Yes
CISA KEV Release Date N/A
CISA KEV Due Date N/A
Exploitation Probability Percentile (EPSS) 86.6
Exploitation Probability (EPSS) 3
Sources
NVD
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2025-12-09
Published
2025-12-09
Added to CISA KEV
Exploited in the wild