CVE-2017-0148
CVE-2017-0148 is a security flaw in Microsoft SMBv1 server. Attackers can run their own code on Microsoft SMBv1 server. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 6 Apr 2022, and says ransomware gangs have used it.[1]
Microsoft SMBv1 server is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff. Microsoft has published a fix or advice.
Description
CISA calls it a remote code execution in Microsoft SMBv1 server. In its words: “The SMBv1 server in Microsoft allows remote attackers to execute arbitrary code via crafted packets.”[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-2017-0146.”[2]
The underlying weakness is improper input validation (CWE-20), in MITRE’s list of common software weaknesses.
It scores 8.1 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 SMBv1 server.
Most families won’t have Microsoft SMBv1 server; it’s for whoever looks after IT at work.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 6 Apr 2022, 1,846 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 27 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 99%. 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]
- Check whether you use it.Microsoft SMBv1 server is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
- Send this page to your IT person.Ask them to confirm it’s fixed, or not in use. CISA gave US government agencies until 27 Apr 2022 to fix it.
- If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.
You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 8.1.[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 99%.[4] |
See also
Other Microsoft SMBv1 server flaws
- CVE-2017-0147: windows SMBv1 information disclosure ·
Other Microsoft flaws
- CVE-2026-96951, Microsoft Windows: command injection ·
- CVE-2026-65660, Microsoft SharePoint: code injection ·
- CVE-2026-85880, Microsoft Windows: heap-based buffer overflow ·
- CVE-2026-81963, Microsoft Windows: link following ·
- CVE-2019-1068, Microsoft SQL Server: remote code execution ·
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-2021-3156, Sudo: heap-based buffer overflow ·
- CVE-2021-31166, Microsoft HTTP Protocol Stack: remote code execution ·
Every Microsoft flaw on CISA’s list · Everything added in April 2022
References
- ^ Cybersecurity and Infrastructure Security Agency. “Microsoft SMBv1 Server Remote Code Execution Vulnerability”. Known Exploited Vulnerabilities Catalog, added 6 Apr 2022.
- ^ National Institute of Standards and Technology. “CVE-2017-0148 Detail”. National Vulnerability Database, published 17 Mar 2017.
- ^ Microsoft. Advisories and fixes: portal.msrc.microsoft.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.994, percentile 99.9, 31 Oct 2026.
- CVE Program. “CVE-2017-0148”. 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.