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Threats / Microsoft / CVE-2025-33073
CVE-2025-33073 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Microsoft Windows vulnerability

Microsoft Windows SMB Client improper access control vulnerability allows privilege escalation through coerced authentication to attacker-controlled systems via specially crafted scripts.

Verdict

Today item — known-exploited.

An attacker can exploit improper access controls in Windows SMB Client to execute a script that forces a victim machine to authenticate to an attacker-controlled SMB server, enabling privilege escalation on the target system.

CISA KEV Yes · 2025-10-203EPSS 0.64315 (verify live)4Exploit Public PoC5
01

Is it exploitable?

— the evidence, ranked above the score
Exploit 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
7 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 2025-10-20).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.64315 — 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-284 Improper Access Control — weakness family: Authorization / access control.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
NVD ↗Reported
WeaknessCWE-284 · Improper Access ControlAuthorization / access control
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 craft a malicious script designed to coerce the target Windows machine into initiating an SMB connection back to my controlled server.
Business
Attackers gain ability to escalate privileges on Windows systems through SMB authentication coercion, expanding lateral movement and persistence capabilities.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I deliver the script to a victim through social engineering, email, or compromised web content to trigger automatic execution.
Business
Compromised user endpoints become entry points for privilege escalation attacks affecting organizational security posture and access controls.
3

Lateral reach — past segmentation narrative 3

Attacker
I capture or relay the victim's authentication credentials when their machine connects to my SMB server, leveraging the access control flaw.
Business
Credential compromise enables attackers to move laterally within networks and access sensitive systems with elevated privileges.
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)
  • Public PoC available (VulnCheck)
  • 7 reported-exploitation source(s)
  • CWE weakness mapping (NVD)
  • Public exploit availability
  • 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.