CVE-2021-40449 is a use-after-free vulnerability in Win32k's NtGdiResetDC function. As with many other Win32k vulnerabilities, the root cause of this vulnerability lies in the ability to set user-mode callbacks and execute unexpected API functions during execution of those callbacks. The CVE-2021-40449 is triggered when the function ResetDC is executed a second time for the same handle during execution of its own callback.
This is a critical vulnerability in the MSHTML rendering engine. Microsoft Office applications use the MSHTML engine to process and display web content. An adversary who successfully exploits could achieve full control over a target system by using malicious ActiveX controls to execute arbitrary code.



This Update contains the following improvements:



-Default Connection method was changed to HTTPS

-Early Release Warning was removed

-Several "Application Name" in "Supported systems" property were added

-Added html obfuscation when possible to avoid AV detection

-All file names are randomized

-Now users can choose between using cab file method or not