CVE-2020-1040
Published: November 3, 2021
Official Description
Microsoft Hyper-V RemoteFX vGPU contains an improper input validation vulnerability due to the host server failing to properly validate input from an authenticated user on a guest operating system. Successful exploitation allows for remote code execution on the host operating system.
CISA KEV Advisory
Microsoft Hyper-V RemoteFX vGPU Remote Code Execution Vulnerability
Microsoft Hyper-V RemoteFX vGPU contains an improper input validation vulnerability due to the host server failing to properly validate input from an authenticated user on a guest operating system. Successful exploitation allows for remote code execution on the host operating system.
Apply updates per vendor instructions.
Risk Analysis
This vulnerability in Microsoft Hyper-V RemoteFX vGPU involves improper input validation, allowing an authenticated guest user to execute code remotely on the host operating system. Despite a low EPSS score, its high severity and confirmed exploitation in the wild make it a critical issue.
This vulnerability is actively being exploited in the wild and is listed in CISA's KEV catalog, indicating confirmed real-world impact. The nature of the flaw suggests it is remotely exploitable once an authenticated user is on a guest OS.
Microsoft Hyper-V users should apply all available security updates to address this vulnerability. Ensure proper network segmentation and least privilege principles are enforced for guest operating systems.
Technical Analysis
CVE-2020-1040 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
CISA has added CVE-2020-1040 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.
Affected Vendors & Products
Exploit & PoC Resources
All References (1)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2020-1040 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
- !CISA KEV: Federal agencies must patch per BOD 22-01 timeline
- !Active exploitation confirmed — treat as P1