Threats / Microsoft / CVE-2025-29824
CVE-2025-29824
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-08-04
Microsoft Windows vulnerability
Microsoft Windows Common Log File System (CLFS) Driver use-after-free vulnerability allows authorized attackers to elevate privileges locally.
Verdict
Today item, not a backlog item.
A use-after-free flaw in the Windows CLFS Driver enables privilege escalation from an authenticated local context. Active exploitation and ransomware deployment indicate immediate operational risk despite requiring prior system access.
CISA KEV Yes · 2025-04-085Ransomware use Flagged5EPSS 0.13475 (verify live)6Exploit Public PoC7CVSS 7.83CISA SSVC Exploitation: active · Automatable: no · Impact: total4
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Public proof-of-concept exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
29 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 2025-04-08), flagged for known ransomware use.
Probability (EPSS)
EPSS 0.13475 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 7.8 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C) · Affected: Microsoft, Windows. Confirm exact fixed builds in the vendor advisory.CVSS — CNA-assigned (CVE.org), version 3.1, set at disclosure.
Weakness (CWE)
Mapped to CWE-416 Use After Free — weakness family: Memory safety.CWE — CNA-assigned (CVE.org); the weakness class drives how the flaw is exploited.
CISA SSVC (triage disposition)
Exploitation: active · Automatable: no · Technical Impact: totalCISA's own stakeholder-specific triage inputs, published in the CVE record (CISA Coordinator role). NOTE: this is CISA's three decision points; the final Act/Attend/Track decision also requires a Mission & Well-being input not published here, so no overall decision is asserted.
Currency of the record
CISA added this to its KEV catalog the same day the CVE record was published.KEV lag = CISA-KEV dateAdded − CVE.org datePublished; a floor on how long the known-exploited flaw sat in the public record before the federal catalog listed it. Severity/weakness here is CNA- or CISA-assigned (current at disclosure), independent of NVD's analysis backlog.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution 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 board1
Front door — unauthenticated access narrative 1
Attacker
I gain initial access to a Windows system as a standard user or service account.
Business
An insider or compromised account provides an entry point for lateral movement within the organization.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I trigger the use-after-free condition in the CLFS Driver through crafted system calls or file operations.
Business
The vulnerability is reliably exploitable, enabling attackers to move from low-privilege to system-level access.
3
Lateral reach — past segmentation narrative 3
Attacker
I execute arbitrary code with SYSTEM privileges after successful privilege escalation.
Business
Attackers gain full control of the compromised host, bypassing security controls and enabling data exfiltration or lateral spread.
4
Data at risk — exfiltration narrative 4
Attacker
I deploy ransomware or persistence mechanisms across the network using elevated access.
Business
Active ransomware campaigns exploiting this flaw result in operational disruption, data encryption, and financial extortion demands.
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