01 Record
CVE-2021-33742
Windows MSHTML Platform Remote Code Execution Vulnerability
HighKEVPUBLISHEDCNA: microsoft
CNA base score7.5 CVSS v3.xCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C
02 Description
Windows MSHTML Platform Remote Code Execution Vulnerability
03 Exploitation and scoring
- Exploitation
- Exploited in the wild. Listed in the CISA Known Exploited Vulnerabilities catalog on 2021-11-03. Federal remediation due 2021-11-17.
- SSVC decision
- ExploitationactiveCISA reports credible evidence of active exploitation.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.
- EPSS probability
- 59.40% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 99.0% of scored records. A rank, not a probability.
- NVD base score
- 7.5 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
- NVD analysis status
- Analyzed. NVD last modified this record on 2026-06-17.
- Red Hat severity
- No Red Hat rating. Red Hat rates the CVEs that affect its products.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2021-06-08 22:46Z5 YR AGO
- Last updated
- 2025-10-21 23:25Z1 YR AGO
- Reserved
- 2021-05-28
- Assigning CNA
- microsoft
- Record state
- PUBLISHED
- Severity
- High (CVSS 7.5)
- CNA CVSS vector
- 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
- Weaknesses
- CWE-787Out-of-bounds WriteBase
- Data version
- 5.1
- Document digest
- 9f465d51fbdb9fb2ff3e109e37e12e1ddeba90f78304ea58f9e9cd2b7b9c65b2
05 Affected products
VendorProductVersionsPlatforms
MicrosoftWindows 10 Version 180910.0.0 to < 10.0.17763.199932-bit Systems, x64-based Systems, ARM64-based Systems
MicrosoftWindows 10 Version 190910.0.0 to < 10.0.18363.162132-bit Systems, x64-based Systems, ARM64-based Systems
MicrosoftWindows 10 Version 21H110.0.0 to < 10.0.19043.1052x64-based Systems, ARM64-based Systems, 32-bit Systems
MicrosoftWindows 10 Version 200410.0.0 to < 10.0.19041.105232-bit Systems, ARM64-based Systems, x64-based Systems
MicrosoftWindows 8.16.3.0 to < 6.3.9600.20045, 6.3.0 to < 1.0.0.032-bit Systems, x64-based Systems, ARM64-based Systems
MicrosoftWindows Server 2008 Service Pack 26.0.0 to < 6.0.6003.21137, 6.0.0 to < publication32-bit Systems
MicrosoftWindows Server 2008 Service Pack 26.0.0 to < 6.0.6003.21137, 6.0.0 to < publicationx64-based Systems
MicrosoftWindows Server 2008 R2 Service Pack 16.1.0 to < 6.1.7601.25632, 6.1.0 to < publicationx64-based Systems