NewsCompaniesFlawsGuides
Get the app

CVE-2017-0146

From Exploited flaws, HARD’s guide to the flaws being used in attacks · Checked
This article is about a flaw in Microsoft Windows. For every flaw being used in attacks, see Exploited flaws; for Microsoft’s, see Microsoft flaws being used in attacks.

CVE-2017-0146 is a security flaw in Microsoft Windows, Microsoft’s operating system for PCs and servers. Attackers can run their own code on Microsoft Windows. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 25 Mar 2022, and says ransomware gangs have used it.[1]

Microsoft Windows is in things households have, such as phones, computers, browsers and everyday apps, so the fix matters at home as much as at work. Microsoft has published a fix or advice.

Description

CISA calls it an SMB remote code execution in Microsoft Windows. In its words: “The SMBv1 server in Microsoft Windows allows remote attackers to perform remote code execution.”[1]

The CVE record adds: “The SMBv1 server in Microsoft Windows Vista SP2; Windows Server 2008 SP2 and R2 SP1; Windows 7 SP1; Windows 8.1; Windows Server 2012 Gold and R2; Windows RT 8.1; and Windows 10 Gold, 1511, and 1607; and Windows Server 2016 allows remote attackers to execute arbitrary code via crafted packets, aka "Windows SMB Remote Code Execution Vulnerability." This vulnerability is different from those described in CVE-2017-0143, CVE-2017-0144, CVE-2017-0145, and CVE-2017-0148.”[2]

The underlying weakness is improper input validation (CWE-20), in MITRE’s list of common software weaknesses.

It scores 8.8 out of 10 on the Common Vulnerability Scoring System, which rates it high, scored by NVD using CVSS 3.1.[2]

Affected versions

NVD’s record doesn’t list version ranges for it; Microsoft’s advisory has them[3]. CISA names the product as Microsoft Windows.

Every device with Microsoft Windows needs the update.

Exploitation

CISA added it to its catalog of known exploited vulnerabilities on 25 Mar 2022, 1,834 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 15 Apr 2022 to fix it.[1] CISA says ransomware gangs have used it.

FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 90%. That’s in the top 1% of the flaws it scores.[4]

CISA assesses it as not automatable: each attack takes some work.

CISA doesn’t say who was attacked, or how.

Fix

Microsoft has published a fix or advice.[3] CISA’s required action: “Apply updates per vendor instructions.”[1]

  1. Update Microsoft Windows now.On Windows: Settings, Windows Update, Check for updates, then restart. Office updates come the same way, or from any Office app: File, Account, Update Options. Then turn on automatic updates, so the next fix arrives on its own.
  2. If there’s no update, stop using it.CISA’s advice when a flaw being used in attacks has no fix is to stop using the product until it does.

Timeline

DateEvent
The flaw is made public in the National Vulnerability Database, with a severity score of 8.8.[2]
CISA adds it to its catalog of flaws known to be used in attacks, noting that ransomware gangs have used it.[1]
CISA’s deadline for US government agencies to fix it.[1]
FIRST puts the odds of it being used in attacks in the next 30 days at 90%.[4]

See also

Other Microsoft Windows flaws

Other improper input validation flaws

  • CVE-2026-93952, Arista VeloCloud Orchestrator: improper input validation ·
  • CVE-2026-12569, PTC Windchill and FlexPLM: improper input validation ·
  • CVE-2026-34910, Ubiquiti UniFi OS: improper input validation ·
  • CVE-2026-6973, Ivanti Endpoint Manager Mobile (EPMM): improper input validation ·
  • CVE-2026-34197, Apache ActiveMQ: improper input validation ·

Added the same day

  • CVE-2022-26318, WatchGuard Firebox and XTM Appliances: arbitrary code execution ·
  • CVE-2022-26143, Mitel MiCollab, MiVoice Business Express: access control ·
  • CVE-2022-21999, Microsoft Windows: print spooler privilege escalation ·
  • CVE-2021-42237, Sitecore XP: remote command execution ·
  • CVE-2021-22941, Citrix ShareFile: improper access control ·

Every Microsoft flaw on CISA’s list · Everything added in March 2022

References

  1. ^ Cybersecurity and Infrastructure Security Agency. “Microsoft Windows SMB Remote Code Execution Vulnerability”. Known Exploited Vulnerabilities Catalog, added 25 Mar 2022.
  2. ^ National Institute of Standards and Technology. “CVE-2017-0146 Detail”. National Vulnerability Database, published 17 Mar 2017.
  3. ^ Microsoft. Advisories and fixes: portal.msrc.microsoft.com.
  4. ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.898, percentile 99.8, 31 Oct 2026.
  5. CVE Program. “CVE-2017-0146”. The official CVE record.

This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.