#Windows MSHTML Platform

**What kind of security feature could be bypassed by successfully exploiting this vulnerability?** A security feature bypass vulnerability exists when the MSHTML platform fails to validate the correct Security Zone of requests for specific URLs. This could allow an attacker to cause a user to access a URL in a less restricted Internet Security Zone than intended. To exploit this vulnerability, an attacker could email or otherwise provide a specially crafted URL to a victim and convince them to click on it. The security update addresses the vulnerability by correcting security feature behavior to properly map affected URLs to the correct Security Zone.

**According to the CVSS metric, successful exploitation of this vulnerability could lead to some loss of integrity (I:L) and some loss of availability (A:L). What does that mean for this vulnerability?** An attacker can craft a malicious URL that would evade zone checks, resulting in a limited loss of integrity and availability of the victim machine.

**According to the CVSS metric, the attack vector is local (AV:L). Why does the CVE title indicate that this is a remote code execution?** The word **Remote** in the title refers to the location of the attacker. This type of exploit is sometimes referred to as Arbitrary Code Execution (ACE). The attack itself is carried out locally. For example, when the score indicates that the **Attack Vector** is **Local** and **User Interaction** is **Required**, this could describe an exploit in which an attacker, through social engineering, convinces a victim to download and open a specially crafted file from a website which leads to a local attack on their computer.

*The Security Updates table indicates that this vulnerability affects all supported versions of Microsoft Windows. Why are IE Cumulative updates listed for Windows Server 2008, Windows 7, Windows Server 2008 R2, Windows Server 2012, Windows 8.1, and Windows Server 2012 R2?* While Microsoft has announced retirement of the Internet Explorer 11 application on certain platforms and the Microsoft Edge Legacy application is deprecated, the underlying MSHTML, EdgeHTML, and scripting platforms are still supported. The MSHTML platform is used by Internet Explorer mode in Microsoft Edge as well as other applications through WebBrowser control. The EdgeHTML platform is used by WebView and some UWP applications. The scripting platforms are used by MSHTML and EdgeHTML but can also be used by other legacy applications. Updates to address vulnerabilities in the MSHTML platform and scripting engine are included in the IE Cumulative Updates; EdgeHTML and Chakra changes are not applicable to those plat...

By default, Microsoft Office opens documents from the internet in Protected View or Application Guard for Office both of which prevent the current attack. * For information about Protected View, see What is Protected View?. * For information about Application Guard for Office, see Application Guard for Office. Customers of Microsoft Defender for Endpoint can enable attack surface reduction rule "BlockOfficeCreateProcessRule" that blocks Office apps from creating child processes. Creating malicious child processes is a common malware strategy. For more information see Use attack surface reduction rules to prevent malware infection.