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Threats / Microsoft / CVE-2017-0148
CVE-2017-0148 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Microsoft SMBv1 server vulnerability

SMBv1 server in Microsoft products allows remote attackers to execute arbitrary code via crafted packets. This vulnerability has been actively exploited in the wild and leveraged in ransomware campaigns.

Verdict

Today item, not a backlog item.

Critical remote code execution vulnerability in SMBv1 with high real-world exploitation activity. The vulnerability enables unauthenticated attackers to achieve code execution on affected systems, facilitating widespread ransomware deployment and data compromise.

CISA KEV Yes · 2022-04-063Ransomware use Flagged3EPSS 0.99373 (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
9 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 2022-04-06), flagged for known ransomware use.
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.99373 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Microsoft, SMBv1 server. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-20 Improper Input Validation.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
NVD ↗Reported
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 malicious SMBv1 packets to trigger memory corruption on the target server.
Business
Attackers gain remote code execution capability without authentication, enabling rapid lateral movement across enterprise networks.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I execute arbitrary code with system privileges on the compromised host.
Business
Complete system compromise allows deployment of ransomware, data exfiltration, and persistence mechanisms across the organization.
3

Lateral reach — past segmentation narrative 3

Attacker
I propagate the exploit to other systems sharing network access to SMBv1 services.
Business
Widespread infection across infrastructure leads to operational shutdown, financial extortion, and regulatory compliance violations.
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)
  • Ransomware-use flag (CISA)
  • EPSS probability (FIRST)
  • Public PoC available (VulnCheck)
  • 9 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.