CVE-2021-40454

Local sensitive-data disclosure

Published Oct 13, 2021 · Updated Aug 4, 2024

Information disclosure in Microsoft Rich Text Edit Control across affected Windows and Office releases allows local users to read sensitive data. Microsoft has not published the specific Rich Text Edit Control operation or data-handling error that exposes the information. Exploitation requires local low-privileged access, needs no user interaction, and is limited to confidentiality impact with no reported modification or service interruption.

CVSS severity5.5
Medium
EPSS probability0.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Microsoft Rich Text Edit Control across affected Windows and Office releases allows local users to read sensitive data. Microsoft has not published the specific Rich Text Edit Control operation or data-handling error that exposes the information. Exploitation requires local low-privileged access, needs no user interaction, and is limited to confidentiality impact with no reported modification or service interruption.

The record

CVE
CVE-2021-40454
Published
Oct 13, 2021
Updated
Aug 4, 2024
Vendor
Microsoft
Product
Windows 10 Version 1507
Classifications
CWE-312, CAPEC-37, T1005
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 13, 2021CVE 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=10.0.0 <10.0.10240.19086

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Microsoft · Windows 10 Version 1507version=10.0.0 <10.0.10240.19086
Microsoft · Windows Server 2019version=10.0.0 <10.0.17763.2237
Microsoft · Windows 10 Version 21H1version=10.0.0 <10.0.19043.1288
Microsoft · Microsoft Office 2016version=16.0.0 <16.0.5227.1000
Microsoft · Microsoft Office 2019version=19.0.0 <https://aka.ms/OfficeSecurityReleases
Microsoft · Windows 10 Version 1909version=10.0.0 <10.0.18363.1854
Microsoft · Microsoft Office LTSC for Mac 2021version=16.0.1 <16.54.21101001
Microsoft · Windows 8.1version=6.3.0 <6.3.9600.20144
Microsoft · Windows Server 2016 (Server Core installation)version=10.0.0 <10.0.14393.4704
Microsoft · Windows 11 version 21H2version=10.0.0 <10.0.22000.258
Microsoft · Windows Server 2012 (Server Core installation)version=6.2.0 <6.2.9200.23490
Microsoft · Windows Server 2012version=6.2.0 <6.2.9200.23490
Microsoft · Windows Server, version 2004version=10.0.0 <10.0.19041.1288
Microsoft · Windows Server 2016version=10.0.0 <10.0.14393.4704
Microsoft · Microsoft Office 2013version=15.0.0 <15.0.5389.1000
Microsoft · Windows 10 Version 20H2version=10.0.0 <10.0.19042.1288
Microsoft · Windows Server 2012 R2 (Server Core installation)version=6.3.0 <6.3.9600.20144
Microsoft · Windows Server 2019 (Server Core installation)version=10.0.0 <10.0.17763.2237
Microsoft · Microsoft Office 2019 for Macversion=16.0.0 <16.54.21101001
Microsoft · Microsoft Office LTSC 2021version=16.0.1 <https://aka.ms/OfficeSecurityReleases
Microsoft · Windows Server version 20H2version=10.0.0 <10.0.19042.1288
Microsoft · Windows 10 Version 1607version=10.0.0 <10.0.14393.4704
Microsoft · Windows Server 2022version=10.0.0 <10.0.20348.288
Microsoft · Windows 10 Version 2004version=10.0.0 <10.0.19041.1288
Microsoft · Windows 10 Version 1809version=10.0.0 <10.0.17763.2237
Microsoft · Windows Server 2012 R2version=6.3.0 <6.3.9600.20144
Microsoft · Microsoft 365 Apps for enterpriseversion=16.0.1 <https://aka.ms/OfficeSecurityReleases

Published CVSS scores

2.1NIST NVDAV:L/AC:L/Au:N/C:P/I:N/A:N
5.5Microsoft CorporationCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-312Cleartext Storage of Sensitive Information
CAPEC-37Retrieve Embedded Sensitive Data
T1005Data from Local System

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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