We have investigated reports of a spoofing vulnerability in AppX installer that affects Microsoft Windows. Microsoft is aware of attacks that attempt to exploit this vulnerability by using specially crafted packages that include the malware family known as Emotet/Trickbot/Bazaloader. An attacker could craft a malicious attachment to be used in phishing campaigns. The attacker would then have to convince the user to open the specially crafted attachment. 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. Please see the Security Updates table for the link to the updated app. Alternatively you can download and install the Installer using the links provided in the FAQ section. Please see the Mitigations and Workaround sections for important information about steps you can take to protect your system from this vulnerability. December 27 2023 Update: In recent months, Microsoft Threat Intelligence has seen an increase in activity from threat actors leveraging social engineering and phishing techniques to target Windows OS users and utilizing the ms-appinstaller URI scheme. To address this increase in activity, we have updated the App Installer to disable the ms-appinstaller protocol by default and recommend other potential mitigations.

Microsoft SharePoint Elevation of Privilege Vulnerability

Microsoft Message Queuing (MSMQ) Remote Code Execution Vulnerability

Microsoft On-Prem Data Gateway Security Feature Bypass Vulnerability

Microsoft SharePoint Server Spoofing Vulnerability

Remote Desktop Protocol Remote Code Execution Vulnerability

Microsoft Exchange Server Elevation of Privilege Vulnerability

Microsoft Exchange Remote Code Execution Vulnerability

Microsoft SharePoint Server Spoofing Vulnerability

Microsoft Excel Security Feature Bypass Vulnerability

Microsoft SharePoint Server Spoofing Vulnerability

Microsoft Exchange 2003 and Outlook Web Access (OWA), when configured to use NTLM authentication, does not properly reuse HTTP connections, which can cause OWA users to view mailboxes of other users when Kerberos has been disabled as an authentication method for IIS 6.0, e.g. when SharePoint Services 2.0 is installed.

A remote code execution vulnerability exists in Remote Desktop Services – formerly known as Terminal Services – when an authenticated attacker abuses clipboard redirection, aka 'Remote Desktop Services Remote Code Execution Vulnerability'.

An elevation of privilege vulnerability exists when Azure DevOps Server and Team Foundation Services improperly handle pipeline job tokens, aka 'Azure DevOps Server and Team Foundation Services Elevation of Privilege Vulnerability'. This CVE ID is unique from CVE-2020-0815.

An elevation of privilege vulnerability exists when Azure DevOps Server and Team Foundation Services improperly handle pipeline job tokens, aka 'Azure DevOps Server and Team Foundation Services Elevation of Privilege Vulnerability'. This CVE ID is unique from CVE-2020-0758.

An remote code execution vulnerability exists in Microsoft Dynamics Business Central, aka 'Dynamics Business Central Remote Code Execution Vulnerability'.

Windows Encrypting File System (EFS) Elevation of Privilege Vulnerability

Adobe Genuine Service versions 7.3 (and earlier) are affected by a privilege escalation vulnerability in the AGSService installer. An authenticated attacker could leverage this vulnerability to achieve read / write privileges to execute arbitrary code. User interaction is required to abuse this vulnerability.

A security feature bypass vulnerability exists where a NETLOGON message is able to obtain the session key and sign messages. To exploit this vulnerability, an attacker could send a specially crafted authentication request. An attacker who successfully exploited this vulnerability could access another machine using the original user privileges. The issue has been addressed by changing how NTLM validates network authentication messages.

A remote code execution vulnerability exists in Remote Desktop Services - formerly known as Terminal Services - when an authenticated attacker abuses clipboard redirection, aka 'Remote Desktop Services Remote Code Execution Vulnerability'.

Outlook for Android Elevation of Privilege Vulnerability

Windows OLE Remote Code Execution Vulnerability

Microsoft Exchange Remote Code Execution Vulnerability

Microsoft SharePoint Elevation of Privilege Vulnerability

Adobe Flash Player version 27.0.0.159 and earlier has a flawed bytecode verification procedure, which allows for an untrusted value to be used in the calculation of an array index. This can lead to type confusion, and successful exploitation could lead to arbitrary code execution.