---
title: "CVE-2021-33742: Windows MSHTML Platform Remote Code… | CubePath"
description: "Windows MSHTML Platform Remote Code Execution Vulnerability"
language: en
source: https://cubepath.com/security/cve/CVE-2021-33742
---
# CVE-2021-33742: Windows MSHTML Platform Remote Code… | CubePath
## Description
Windows MSHTML Platform Remote Code Execution Vulnerability
Official description from the CVE record, published by microsoft. Copyright © 1999-2026 The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CVE license. [View the record on cve.org](https://www.cve.org/CVERecord?id=CVE-2021-33742)
## Key data
### CVSS 3.1 High 7.5
Score published by microsoft in the CVE record.
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C
| Metric | Value | What it means |
| ---------------------- | --------- | ----------------------------------------------------------------------------------------- |
| Attack vector | Network | The vulnerable component can be reached over a network, possibly from the Internet. |
| Attack complexity | High | The attack depends on conditions outside the attacker's control, so it takes preparation. |
| Privileges required | None | No account or privileges are needed. |
| User interaction | Required | A user has to do something first, such as opening a file or following a link. |
| Scope | Unchanged | The impact stays within the vulnerable component. |
| Confidentiality impact | High | Serious or total effect on the secrecy of data. |
| Integrity impact | High | Serious or total effect on the trustworthiness of data. |
| Availability impact | High | Serious or total effect on availability. |
CVSS is owned and managed by FIRST.Org, Inc. (FIRST) and is used by permission. Each CVSS score on this site is shown together with its vector string, as published in the CVE record by the source named next to it. Learn more at [first.org/cvss](https://www.first.org/cvss/) .
### EPSS
Exploit Prediction Scoring System by FIRST: an estimate of the probability that exploitation activity will be observed in the next 30 days.
Score
0.59407 (59.4% probability)
Percentile
99.1%
Scores of
Nov 10, 2026
Model
v2026.06.15
### CISA Known Exploited Vulnerabilities
This CVE is listed in the CISA KEV catalog.
Name in the catalog
Microsoft Windows MSHTML Platform Remote Code Execution Vulnerability
Added to the catalog
Nov 3, 2021
Federal due date
Nov 17, 2021
### CISA assessment as of Feb 4, 2025
Stakeholder-Specific Vulnerability Categorization (SSVC) decision points added by CISA.
Exploitation
Recorded by CISA as active
Automatable
no
Technical impact
total
### Weakness (CWE)
CWE catalog version 5.0.
CWE names: Copyright © 2006-2026, The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CWE license.
- [CWE-787](https://cwe.mitre.org/data/definitions/787.html) Out-of-bounds Write
## Affected products
Products listed in the CVE record, as the CNA published them.
- Microsoft Windows 10 Version 1809
- affected: 10.0.0 up to before 10.0.17763.1999
- Microsoft Windows Server 2019
- affected: 10.0.0 up to before 10.0.17763.1999
- Microsoft Windows 10 Version 1909
- affected: 10.0.0 up to before 10.0.18363.1621
- Microsoft Windows 10 Version 21H1
- affected: 10.0.0 up to before 10.0.19043.1052
- Microsoft Windows 10 Version 2004
- affected: 10.0.0 up to before 10.0.19041.1052
- Microsoft Windows 10 Version 20H2
- affected: 10.0.0 up to before 10.0.19042.1052
- Microsoft Windows 10 Version 1507
- affected: 10.0.0 up to before 10.0.10240.18967
- Microsoft Windows 10 Version 1607
- affected: 10.0.0 up to before 10.0.14393.4467
- Microsoft Windows Server 2016
- affected: 10.0.0 up to before 10.0.14393.4467
- Microsoft Windows 7
- affected: 6.1.0 up to before 6.1.7601.25632
- affected: 6.1.0 up to before publication
- Microsoft Windows 7 Service Pack 1
- affected: 6.1.0 up to before 6.1.7601.25632
- affected: 6.1.0 up to before publication
- Microsoft Windows 8.1
- affected: 6.3.0 up to before 6.3.9600.20045
- affected: 6.3.0 up to before 1.0.0.0
- Microsoft Windows Server 2008 Service Pack 2
- affected: 6.0.0 up to before 6.0.6003.21137
- affected: 6.0.0 up to before publication
- Microsoft Windows Server 2008 Service Pack 2
- affected: 6.0.0 up to before 6.0.6003.21137
- affected: 6.0.0 up to before publication
- Microsoft Windows Server 2008 R2 Service Pack 1
- affected: 6.1.0 up to before 6.1.7601.25632
- affected: 6.1.0 up to before publication
- Microsoft Windows Server 2012
- affected: 6.2.0 up to before 6.2.9200.23372
- affected: 6.2.0 up to before 1.0.0.0
- Microsoft Windows Server 2012 R2
- affected: 6.3.0 up to before 6.3.9600.20045
- affected: 6.3.0 up to before 1.0.0.0
## References
Links listed in the CVE record. They lead to other sites, which CubePath does not control.
- [portal.msrc.microsoft.com/en-US/security-guidance/advisory/…](https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-33742)
## Timeline
1. ID reserved May 28, 2021
2. Record published Jun 8, 2021
3. Added to CISA KEV Nov 3, 2021
4. Record last updated Oct 21, 2025
## Look up another CVE
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Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 20:03 UTC. [Sources and licenses](https://cubepath.com/security/cve/legal)