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Threats / Microsoft / CVE-2025-62221
CVE-2025-62221 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Microsoft Windows vulnerability

Microsoft Windows Cloud Files Mini Filter Driver contains a use-after-free vulnerability allowing authorized attackers to elevate privileges locally.

Verdict

Today item — known-exploited.

A use-after-free flaw in the Windows Cloud Files Mini Filter Driver enables local privilege escalation for authenticated users. The vulnerability is actively exploited in the wild, though not associated with ransomware campaigns.

CISA KEV Yes · 2025-12-093EPSS 0.02342 (verify live)4
01

Is it exploitable?

— the evidence, ranked above the score
Reported exploitation
6 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2025-12-09).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.02342 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Microsoft, Windows. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-416 Use After Free — weakness family: Memory safety.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
NVD ↗Reported
WeaknessCWE-416 · Use After FreeMemory safety
02

Who’s exploiting it?

— attribution turns risk into urgency
Attribution not established

No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.

03

Why it matters

— the attack path, told twice: adversary, then board
1

Front door — unauthenticated access narrative 1

Attacker
I gain initial access as an authorized local user with limited privileges.
Business
An insider or compromised standard user account exists within the environment.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I trigger the use-after-free condition in the Cloud Files Mini Filter Driver through crafted system calls.
Business
The kernel-mode driver processes untrusted input without proper memory lifecycle management.
3

Lateral reach — past segmentation narrative 3

Attacker
I execute arbitrary code with elevated system privileges by exploiting the freed memory region.
Business
An attacker gains SYSTEM-level access, enabling full system compromise and lateral movement.
04

What to do

— defensible action
  • Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05

Coverage & confidence

— what we know, and what we don’t

Established (cited)

  • KEV listing (CISA)
  • EPSS probability (FIRST)
  • 6 reported-exploitation source(s)
  • CWE weakness mapping (NVD)
  • Catalogued by microsoft (CNA)
  • Coverage gaps — stated, not hidden

  • No EUVD / GCVE mirror in feed — single-authority dependency for the identifier.
  • EPSS & exposure are time-varying; verify live at the source.
  • Threat-actor attribution not established from feed data — absence of a name is not absence of compromise.
  • No finder/reporter credit recorded in the public CVE entry — the work behind this find is unattributed.
  • Disclosure & credit2
    Catalogued by microsoftCNA
    Credited with finding itNo finder named in the public CVE record — the work behind this find is unattributed.