CVE-2020-0621

Password-policy bypass via third-party filter calls

Published Jan 14, 2020 · Updated Aug 4, 2024

Security feature bypass in Microsoft Windows and Windows Server allows local users to evade password-update protections. The flaw occurs when Windows invokes third-party password filters during an update, but Microsoft has not disclosed the mishandled validation or state transition. Exploitation requires high local privileges and compromises password-policy integrity without reported confidentiality or availability impact.

CVSS severity4.4
Medium
EPSS probability0.97%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Security feature bypass in Microsoft Windows and Windows Server allows local users to evade password-update protections. The flaw occurs when Windows invokes third-party password filters during an update, but Microsoft has not disclosed the mishandled validation or state transition. Exploitation requires high local privileges and compromises password-policy integrity without reported confidentiality or availability impact.

The record

CVE
CVE-2020-0621
Published
Jan 14, 2020
Updated
Aug 4, 2024
Vendor
Microsoft
Product
Windows
Classifications
CWE-613
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Jan 14, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10 Version 1709 for 32-bit Systems
  2. Affected versionversion=10 Version 1709 for ARM64-based Systems
  3. Affected versionversion=10 Version 1709 for x64-based Systems
  4. Affected versionversion=10 Version 1803 for 32-bit Systems
  5. Affected versionversion=10 Version 1803 for ARM64-based Systems
  6. Affected versionversion=10 Version 1803 for x64-based Systems
  7. Affected versionversion=10 Version 1809 for 32-bit Systems
  8. Affected versionversion=10 Version 1809 for ARM64-based Systems
  9. Affected versionversion=10 Version 1809 for x64-based Systems

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Microsoft · Windowsversion=10 Version 1709 for 32-bit Systems; version=10 Version 1709 for ARM64-based Systems; version=10 Version 1709 for x64-based Systems; version=10 Version 1803 for 32-bit Systems; version=10 Version 1803 for ARM64-based Systems; version=10 Version 1803 for x64-based Systems; version=10 Version 1809 for 32-bit Systems; version=10 Version 1809 for ARM64-based Systems; version=10 Version 1809 for x64-based Systems
Microsoft · Windows Serverversion=2019; version=2019 (Core installation); version=version 1803 (Core Installation)

Published CVSS scores

2.1NIST NVDAV:L/AC:L/Au:N/C:N/I:P/A:N
4.4NIST NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-613Insufficient Session Expiration

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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