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CVE-2021-40444

high · 8.8Actively exploited

On the CISA Known Exploited Vulnerabilities catalog

Apply updates per vendor instructions.

Added 2021-11-03Remediation due 2021-11-17

Microsoft is investigating reports of a remote code execution vulnerability in MSHTML that affects Microsoft Windows. Microsoft is aware of targeted attacks that attempt to exploit this vulnerability by using specially-crafted Microsoft Office documents. An attacker could craft a malicious ActiveX control to be used by a Microsoft Office document that hosts the browser rendering engine. The attacker would then have to convince the user to open the malicious document. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights. Microsoft Defender Antivirus and Microsoft Defender for Endpoint both provide detection and protections for the known vulnerability. Customers should keep antimalware products up to date. Customers who utilize automatic updates do not need to take additional action. Enterprise customers who manage updates should select the detection build 1.349.22.0 or newer and deploy it across their environments. Microsoft Defender for Endpoint alerts will be displayed as: “Suspicious Cpl File Execution”. Upon completion of this investigation, Microsoft will take the appropriate action to help protect our customers. This may include providing a security update through our monthly release process or providing an out-of-cycle security update, depending on customer needs. Please see the Mitigations and Workaround sections for important information about steps you can take to protect your system from this vulnerability. UPDATE September 14, 2021: Microsoft has released security updates to address this vulnerability. Please see the Security Updates table for the applicable update for your system. We recommend that you install these updates immediately. Please see the FAQ for important information about which updates are applicable to your system.

8.8
CVSS
97.5%
EPSS (exploit prob.)
100th
EPSS percentile
2021-09-15
Published

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:L

Weaknesses

CWE-22

Affected products

VendorProductAffected versions
microsoftwindows_10_1507< 10.0.10240.19060
microsoftwindows_10_1607< 10.0.14393.4651
microsoftwindows_10_1809< 10.0.17763.2183
microsoftwindows_10_1909< 10.0.18363.1801
microsoftwindows_10_2004< 10.0.19041.1237
microsoftwindows_10_20h2< 10.0.19042.1237
microsoftwindows_10_21h1< 10.0.19043.1237
microsoftwindows_7all versions
microsoftwindows_8.1all versions
microsoftwindows_rt_8.1all versions
microsoftwindows_server_2004< 10.0.19041.1237
microsoftwindows_server_2008all versions
microsoftwindows_server_2008r2
microsoftwindows_server_2012all versions
microsoftwindows_server_2012all versions
microsoftwindows_server_2016< 10.0.14393.4651
microsoftwindows_server_2019< 10.0.17763.2183
microsoftwindows_server_2022< 10.0.20348.230
microsoftwindows_server_20h2< 10.0.19042.1237

Check a specific version with /api/v1/cve/match.

References

Query this programmatically:

curl https://evil-db.io/api/v1/cve/CVE-2021-40444