A zero-day vulnerability in Microsoft Office is being actively exploited in the wild, and while there isn’t currently a patch, the software giant has published workarounds to thwart attacks. CVE-2022-30190, also known as “Follina,” is a remote code execution (RCE) vulnerability affecting the Microsoft Support Diagnostic Tool (MSDT) in Windows.
CVE-2022-30190
Microsoft Windows could allow a remote attacker to execute arbitrary code on the system, caused by a flaw in the Support Diagnostic Tool (MSDT) component. By persuading a victim to open specially-crafted content, an attacker could exploit this vulnerability to execute arbitrary code on the system. Microsoft Support Diagnostics Tool (MSDT) is used by support professionals for troubleshooting.
According to the researcher, maldoc retrieves an HTML file from a server using Word’s template feature. The malicious payload is then obtained via the “ms-msdt: //” URI scheme.
The attackers who successfully exploit this vulnerability can run arbitrary code with the privileges of the calling application. The attacker can then install programs, view, change, delete data, or create new accounts in the context allowed by the user’s permissions. Here are the workaround guidance shared by Microsoft:
Microsoft Windows Server (Server Core installation) 2019
Microsoft Windows Server (Server Core installation) 20H2
Microsoft Windows Server (Server Core installation) 2016
Microsoft Windows Server (Server Core installation) 2012 R2
Microsoft Windows Server (Server Core installation) 2012
Microsoft Windows Server for X64-based systems (Server Core installation) 2008 R2
Microsoft Windows Server for X64-based systems 2008 R2 SP1
Microsoft Windows Server for 32-bit systems (Server Core installation) 2008 SP2
Microsoft Windows Server for 32-bit systems 2008 SP2
Microsoft Windows Server for X64-based systems (Server Core installation) 2008 R2 SP1
Microsoft Windows 10 21H1 for 32-bit Systems
Microsoft Windows 10 21H1 for ARM64-based Systems
Microsoft Windows 10 21H1 for x64-based Systems
Microsoft Windows Server 2022
Microsoft Windows Server (Server Core installation) 2022
Microsoft Windows Server for X64-based systems 2008 SP2
Microsoft Windows 11 x64
Microsoft Windows 11 ARM64
Microsoft Windows 10 21H2 for 32-bit Systems
Microsoft Windows 10 21H2 for ARM64-based Systems
Microsoft Windows 10 21H2 for x64-based Systems
Microsoft Windows Server 2022 Azure Edition Core Hotpatch
Remediation
Use Microsoft Automatic Update to apply the appropriate patch for your system, or the Microsoft Security Update Guide to search for available patches.
Customers using Microsoft Defender Antivirus should turn-on cloud-delivered protection and automatic sample submission.
Customers that use Microsoft Defender for Endpoint can set the “BlockOfficeCreateProcessRule” attack surface reduction rule, which prevents Office apps from generating child processes.
Block the threat indicators at their respective controls.