Actively exploited · Published Jun 8, 2021 · Assigned by microsoft
CVE-2021-33742Windows MSHTML Platform Remote Code Execution Vulnerability
High 7.5 Exploited
In plain English
A high-severity out-of-bounds write in Windows 10 Version 1507 from Microsoft. Attackers are actively exploiting it in the wild (listed by CISA on November 3, 2021). The chance it is exploited in the next 30 days is estimated at 59.4% (higher than 99.1% of all known vulnerabilities). Apply updates per vendor instructions.
Severity (CVSS 3.1)7.5High
Exploit odds (30 days)59.4%top 0.9% of all CVEs
Exploited in the wildYesCISA KEV since Nov 3, 2021
Attack toolingNoneno public tooling known
CISA guidance
Apply updates per vendor instructions.
Federal agencies must remediate by Nov 17, 2021.
Official description
Windows MSHTML Platform Remote Code Execution Vulnerability
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | Windows 10 Version 1809 | 10.0.0 – before 10.0.17763.1999 |
| Microsoft | Windows Server 2019 | 10.0.0 – before 10.0.17763.1999 |
| Microsoft | Windows 10 Version 1909 | 10.0.0 – before 10.0.18363.1621 |
| Microsoft | Windows 10 Version 21H1 | 10.0.0 – before 10.0.19043.1052 |
| Microsoft | Windows 10 Version 2004 | 10.0.0 – before 10.0.19041.1052 |
| Microsoft | Windows 10 Version 20H2 | 10.0.0 – before 10.0.19042.1052 |
| Microsoft | Windows 10 Version 1507 | 10.0.0 – before 10.0.10240.18967 |
| Microsoft | Windows 10 Version 1607 | 10.0.0 – before 10.0.14393.4467 |
| Microsoft | Windows Server 2016 | 10.0.0 – before 10.0.14393.4467 |
| Microsoft | Windows 7 | 6.1.0 – before 6.1.7601.256326.1.0 – before publication |
| Microsoft | Windows 7 Service Pack 1 | 6.1.0 – before 6.1.7601.256326.1.0 – before publication |
| Microsoft | Windows 8.1 | 6.3.0 – before 6.3.9600.200456.3.0 – before 1.0.0.0 |
| Microsoft | Windows Server 2008 Service Pack 2 | 6.0.0 – before 6.0.6003.211376.0.0 – before publication |
| Microsoft | Windows Server 2008 Service Pack 2 | 6.0.0 – before 6.0.6003.211376.0.0 – before publication |
| Microsoft | Windows Server 2008 R2 Service Pack 1 | 6.1.0 – before 6.1.7601.256326.1.0 – before publication |
| Microsoft | Windows Server 2012 | 6.2.0 – before 6.2.9200.233726.2.0 – before 1.0.0.0 |
| Microsoft | Windows Server 2012 R2 | 6.3.0 – before 6.3.9600.200456.3.0 – before 1.0.0.0 |
Weakness: CWE-787 · 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