CVE-2020-1464
CVE-2020-1464 is a security flaw in Microsoft Windows, Microsoft’s operating system for PCs and servers. Attackers can get past a security protection in Microsoft Windows. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 3 Nov 2021.[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. Fixed in version publication.
Description
CISA calls it a spoofing in Microsoft Windows. In its words: “Microsoft Windows contains a spoofing vulnerability when Windows incorrectly validates file signatures, allowing an attacker to bypass security features and load improperly signed files.”[1]
The CVE record adds: “A spoofing vulnerability exists when Windows incorrectly validates file signatures. An attacker who successfully exploited this vulnerability could bypass security features and load improperly signed files. In an attack scenario, an attacker could bypass security features intended to prevent improperly signed files from being loaded. The update addresses the vulnerability by correcting how Windows validates file signatures.”[2]
The underlying weakness is CWE-347, in MITRE’s list of common software weaknesses.
It scores 7.8 out of 10 on the Common Vulnerability Scoring System, which rates it high, scored by the organisation that published the CVE using CVSS 3.1.[2]
Affected versions
NVD’s record lists these fixed versions: in each line, everything before the version shown is affected.[2]
| Product | Fixed in |
|---|---|
| Windows 10 Version 1803 | publication |
| Windows 10 Version 1809 | publication |
| Windows Server 2019 | publication |
| Windows Server 2019 (Server Core installation) | publication |
| Windows 10 Version 1909 | publication |
| Windows Server, version 1909 (Server Core installation) | publication |
| Windows 10 Version 1709 for 32-bit Systems | publication |
| Windows 10 Version 1709 | publication |
Every device with Microsoft Windows needs the update.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 3 Nov 2021, 443 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 3 May 2022 to fix it.[1]
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 39%. That’s in the top 2% 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]
- 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.
- Check you’re on publication or later.Fixed in version publication. Anything older is what attackers are going after.
- 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
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 7.8.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[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 39%.[4] |
See also
Other Microsoft Windows flaws
- CVE-2026-96951: command injection ·
- CVE-2026-85880: heap-based buffer overflow ·
- CVE-2026-81963: link following ·
- CVE-2008-4250: buffer overflow ·
- CVE-2026-32202: protection mechanism failure ·
- CVE-2025-60710: link following ·
Similar flaws
- CVE-2026-5430, WSO2 products: path traversal ·
- CVE-2026-48558, SimpleHelp: authentication bypass ·
- CVE-2025-59718, Fortinet products: improper verification of cryptographic signature ·
- CVE-2020-2021, Palo Alto Networks PAN-OS: authentication bypass ·
- CVE-2022-20703, Cisco Small Business RV160, RV260, RV340, and RV345 Series Routers: small business RV series routers stack-based buffer overflow ·
Added the same day
- CVE-2021-42258, BQE BillQuick Web Suite: SQL injection ·
- CVE-2021-42013, Apache HTTP Server: path traversal ·
- CVE-2021-41773, Apache HTTP Server: path traversal ·
- CVE-2021-40539, Zoho ManageEngine: aDSelfService plus authentication bypass ·
- CVE-2021-40444, Microsoft MSHTML: remote code execution ·
Every Microsoft flaw on CISA’s list · Everything added in November 2021
References
- ^ Cybersecurity and Infrastructure Security Agency. “Microsoft Windows Spoofing Vulnerability”. Known Exploited Vulnerabilities Catalog, added 3 Nov 2021.
- ^ National Institute of Standards and Technology. “CVE-2020-1464 Detail”. National Vulnerability Database, published 17 Aug 2020.
- ^ Microsoft. Advisories and fixes: portal.msrc.microsoft.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.389, percentile 98.6, 31 Oct 2026.
- CVE Program. “CVE-2020-1464”. 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.