CVE-2022-30190
HIGHCVSS Vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Lifecycle Timeline
5Description
A remote code execution vulnerability exists when MSDT is called using the URL protocol from a calling application such as Word. An attacker who successfully exploits this vulnerability can run arbitrary code with the privileges of the calling application. The attacker can then install programs, view, change, or delete data, or create new accounts in the context allowed by the user’s rights. Please see the MSRC Blog Entry for important information about steps you can take to protect your system from this vulnerability.
Analysis
Windows MSDT (Microsoft Support Diagnostic Tool) allows remote code execution when called via the ms-msdt URL protocol from Office documents, known as 'Follina', exploited as a zero-day from April 2022 in targeted attacks.
Technical Context
The vulnerability exploits Office's ability to invoke MSDT via the ms-msdt URL protocol handler. A crafted document contains an HTML reference that loads a page with MSDT protocol invocation, passing arbitrary PowerShell commands through diagnostic parameters. Critically, this bypasses macro blocking because it uses URL protocol handlers, not VBA.
Affected Products
['Microsoft Windows (all supported versions with MSDT)', 'Microsoft Office (as the delivery vector)']
Remediation
Apply Microsoft security update. Disable the ms-msdt URL protocol handler via registry: `reg delete HKEY_CLASSES_ROOT\ms-msdt /f`. Block Office from creating child processes via ASR rules.
Priority Score
Share
External POC / Exploit Code
Leaving vuln.today