An elevation of privilege vulnerability exists in the way that the srmsvc.dll handles objects in memory. An attacker who successfully exploited the vulnerability could execute code with elevated permissions. To exploit the vulnerability, a locally authenticated attacker could run a specially crafted application. The security update addresses the vulnerability by ensuring the srmsvc.dll properly handles objects in memory.

An information disclosure vulnerability exists when the Windows Image Acquisition (WIA) Service improperly discloses contents of its memory. An attacker who successfully exploited the vulnerability could obtain information to further compromise the user’s system. To exploit the vulnerability, an authenticated attacker could connect an imaging device (camera, scanner, cellular phone) to an affected system and run a specially crafted application to disclose information. The security update addresses the vulnerability by correcting how the WIA Service handles objects in memory.

A remote code execution vulnerability exists when the Windows Jet Database Engine improperly handles objects in memory. An attacker who successfully exploited this vulnerability could execute arbitrary code on a victim system. An attacker could exploit this vulnerability by enticing a victim to open a specially crafted file. The update addresses the vulnerability by correcting the way the Windows Jet Database Engine handles objects in memory.

An elevation of privilege vulnerability exists when an attacker establishes a vulnerable Netlogon secure channel connection to a domain controller, using the Netlogon Remote Protocol (MS-NRPC). An attacker who successfully exploited the vulnerability could run a specially crafted application on a device on the network. To exploit the vulnerability, an unauthenticated attacker would be required to use MS-NRPC to connect to a domain controller to obtain domain administrator access. Microsoft is addressing the vulnerability in a phased two-part rollout. These updates address the vulnerability by modifying how Netlogon handles the usage of Netlogon secure channels. For guidelines on how to manage the changes required for this vulnerability and more information on the phased rollout, see How to manage the changes in Netlogon secure channel connections associated with CVE-2020-1472 (updated September 28, 2020). When the second phase of Windows updates become available in Q1 2021, customers will be notified via a revision to this security vulnerability. If you wish to be notified when these updates are released, we recommend that you register for the security notifications mailer to be alerted of content changes to this advisory. See Microsoft Technical Security Notifications.

An elevation of privilege vulnerability exists when the Windows Work Folders Service improperly handles memory. To exploit this vulnerability, an attacker would first have to gain execution on the victim system. An attacker could then run a specially crafted application to elevate privileges. The security update addresses the vulnerability by correcting how the Windows Work Folders Service handles memory.

An elevation of privilege vulnerability exists when Windows improperly handles hard links. An attacker who successfully exploited this vulnerability could overwrite a targeted file leading to an elevated status. To exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially crafted application that could exploit the vulnerability and take control of an affected system. The security update addresses the vulnerability by correcting how Windows handles hard links.

A denial of service vulnerability exists in Windows Remote Desktop Gateway (RD Gateway) when an attacker connects to the target system using RDP and sends specially crafted requests. An attacker who successfully exploited this vulnerability could cause the RD Gateway service on the target system to stop responding. To exploit this vulnerability, an attacker would need to run a specially crafted application against a server which provides RD Gateway services. The update addresses the vulnerability by correcting how RD Gateway handles connection requests.

A spoofing vulnerability exists when Windows incorrectly validates file signatures. An attacker who successfully exploited this vulnerability could bypass security features and load improperly signed files. In an attack scenario, an attacker could bypass security features intended to prevent improperly signed files from being loaded. The update addresses the vulnerability by correcting how Windows validates file signatures.

An information disclosure vulnerability exists in RPC if the server has Routing and Remote Access enabled. An attacker who successfully exploited this vulnerability could obtain information to further compromise the user’s system To exploit this vulnerability, an attacker would need to run a specially crafted application against an RPC server which has Routing and Remote Access enabled. Routing and Remote Access is a non-default configuration; systems without it enabled are not vulnerable. The security update addresses the vulnerability by correcting how the Routing and Remote Access service handles requests.

A remote code execution vulnerability exists in the way that the scripting engine handles objects in memory in Internet Explorer. The vulnerability could corrupt memory in such a way that an attacker could execute arbitrary code in the context of the current user. An attacker who successfully exploited the vulnerability could gain the same user rights as the current user. If the current user is logged on with administrative user rights, an attacker who successfully exploited the vulnerability could take control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. In a web-based attack scenario, an attacker could host a specially crafted website that is designed to exploit the vulnerability through Internet Explorer and then convince a user to view the website. An attacker could also embed an ActiveX control marked "safe for initialization" in an application or Microsoft Office document that hosts the IE rendering engine. The attacker could also take advantage of compromised websites and websites that accept or host user-provided content or advertisements. These websites could contain specially crafted content that could exploit the vulnerability. The security update addresses the vulnerability by modifying how the scripting engine handles objects in memory.

A memory corruption vulnerability exists when Windows Media Foundation improperly handles objects in memory. An attacker who successfully exploited the vulnerability could install programs; view, change, or delete data; or create new accounts with full user rights. There are multiple ways an attacker could exploit the vulnerability, such as by convincing a user to open a specially crafted document, or by convincing a user to visit a malicious webpage. The security update addresses the vulnerability by correcting how Windows Media Foundation handles objects in memory.

An elevation of privilege vulnerability exists when the Windows Kernel API improperly handles registry objects in memory. An attacker who successfully exploited the vulnerability could gain elevated privileges on a targeted system. A locally authenticated attacker could exploit this vulnerability by running a specially crafted application. The security update addresses the vulnerability by helping to ensure that the Windows Kernel API properly handles objects in memory.

An elevation of privilege vulnerability exists when the Windows Kernel API improperly handles registry objects in memory. An attacker who successfully exploited the vulnerability could gain elevated privileges on a targeted system. A locally authenticated attacker could exploit this vulnerability by running a specially crafted application. The security update addresses the vulnerability by helping to ensure that the Windows Kernel API properly handles objects in memory.

A remote code execution vulnerability exists when Windows Media Audio Codec improperly handles objects. An attacker who successfully exploited the vulnerability could take control of an affected system. There are multiple ways an attacker could exploit the vulnerability, such as by convincing a user to open a specially crafted document, or by convincing a user to visit a malicious webpage. The security update addresses the vulnerability by correcting how Windows Media Audio Codec handles objects.

An elevation of privilege vulnerability exists when the Windows Print Spooler service improperly allows arbitrary writing to the file system. An attacker who successfully exploited this vulnerability could run arbitrary code with elevated system privileges. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. To exploit this vulnerability, an attacker would have to log on to an affected system and run a specially crafted script or application. The update addresses the vulnerability by correcting how the Windows Print Spooler Component writes to the file system.

A remote code execution vulnerability exists when Microsoft .NET Framework processes input. An attacker who successfully exploited this vulnerability could take control of an affected system. To exploit the vulnerability, an attacker would need to be able to upload a specially crafted file to a web application. The security update addresses the vulnerability by correcting how .NET Framework processes input.

Integer overflows were discovered in the functions grub_cmd_initrd and grub_initrd_init in the efilinux component of GRUB2, as shipped in Debian, Red Hat, and Ubuntu (the functionality is not included in GRUB2 upstream), leading to a heap-based buffer overflow. These could be triggered by an extremely large number of arguments to the initrd command on 32-bit architectures, or a crafted filesystem with very large files on any architecture. An attacker could use this to execute arbitrary code and bypass UEFI Secure Boot restrictions. This issue affects GRUB2 version 2.04 and prior versions.

GRUB2 contains a race condition in grub_script_function_create() leading to a use-after-free vulnerability which can be triggered by redefining a function whilst the same function is already executing, leading to arbitrary code execution and secure boot restriction bypass. This issue affects GRUB2 version 2.04 and prior versions.

GRUB2 fails to validate kernel signature when booted directly without shim, allowing secure boot to be bypassed. This only affects systems where the kernel signing certificate has been imported directly into the secure boot database and the GRUB image is booted directly without the use of shim. This issue affects GRUB2 version 2.04 and prior versions.

An information disclosure vulnerability exists when the Windows GDI component improperly discloses the contents of its memory, aka 'Windows GDI Information Disclosure Vulnerability'.