Cyber Resilience

CVE-2020-1040

Microsoft Windows Server 2012 r2

CISA KEVActive ExploitationEUVD Exploited
Published
14 July 2020
Modified
29 October 2025
KEV Added
03 November 2021
Patch / advisory
CVSS Score v3.1 9.0
Click a component to see what it means
Raw vectorCVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.069 93th percentile
Risk Priority 89 floored blend · peak EPSS

Summary

CVE-2020-1040 is a critical-severity Improper Input Validation (CWE-20) vulnerability in Microsoft Windows Server 2012. Its CVSS base score is 9.0 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 7% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

A remote code execution vulnerability tracked as CVE-2020-1040 affects the Hyper-V RemoteFX vGPU component on a host server. The flaw stems from improper input validation (CWE-20) when the component processes data originating from an authenticated user on a guest operating system, allowing the issue to be triggered across virtual machine boundaries.

An attacker with an authenticated session inside a guest virtual machine can send specially crafted input over an adjacent network to the host, achieving arbitrary code execution with high impact to confidentiality, integrity, and availability. The CVSS 9.0 vector reflects low attack complexity, no user interaction, and a scope change that extends compromise from the guest to the host hypervisor.

Microsoft and NVIDIA security advisories provide patches and configuration guidance to address the vulnerability on affected Hyper-V hosts, while the CISA known exploited vulnerabilities catalog confirms active tracking of the issue for prioritized remediation.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A remote code execution vulnerability exists when Hyper-V RemoteFX vGPU on a host server fails to properly validate input from an authenticated user on a guest operating system, aka 'Hyper-V RemoteFX vGPU Remote Code Execution Vulnerability'. This CVE ID is…

more

unique from CVE-2020-1032, CVE-2020-1036, CVE-2020-1041, CVE-2020-1042, CVE-2020-1043.

CWE(s)
KEV Date Added
03 November 2021

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1036.001 Invalid Code Signature Stealth
Adversaries may attempt to mimic features of valid code signatures to increase the chance of deceiving a user, analyst, or tool.
T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2020-1350Same product: Microsoft Windows Server 2008both on KEV
CVE-2023-36563Same product: Microsoft Windows Server 2008both on KEV
CVE-2025-32706Same product: Microsoft Windows Server 2008both on KEV
CVE-2012-0151Same product: Microsoft Windows Server 2008both on KEV
CVE-2023-36706Same product: Microsoft Windows Server 2008
CVE-2024-30040Same product: Microsoft Windows Server 2016both on KEV
CVE-2023-36761Same vendor: Microsoftboth on KEV
CVE-2024-43455Same product: Microsoft Windows Server 2008
CVE-2024-21413Same vendor: Microsoftboth on KEV
CVE-2018-8414Same vendor: Microsoftboth on KEV

Affected Assets

microsoft
windows server 2008
r2
microsoft
windows server 2012
all versions, r2
microsoft
windows server 2016
all versions

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 6 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-20

Security testing and developer training directly verify and enforce proper input validation, reducing exploitability of injection and malformed-data weaknesses.

addresses: CWE-20

Security testing and evaluation at multiple SDLC stages directly detects missing or flawed input validation, with the required remediation process ensuring fixes are applied.

addresses: CWE-20

Directly implements checks on information inputs to reject invalid data before processing.

addresses: CWE-20

Spam protection mechanisms perform filtering and detection on inbound/outbound messages, directly compensating for missing or weak input validation of unsolicited content.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require and enforce input validation during development.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Testing against a defined set of requirements and using code review plus vulnerability scanning forces validation of inputs and handling of unanticipated conditions, reducing the chance that malformed data will be accepted.

prevents

Secure-coding guidelines and mandatory security testing (including code scans) compel developers to validate and sanitize inputs at design and implementation time, lowering the incidence of malformed or malicious data reaching downstream components.

prevents

Mandating input controls that include integrity checks and input validation ensures that untrusted data is examined before use, blocking the root cause of many injection and malformed-data weaknesses.

prevents

Security-by-design principles explicitly call for data validation and sanitization at every layer, reducing the chance that malformed or malicious input will be processed without scrutiny.

prevents

Requiring language-specific secure coding standards, peer review, SAST and documented mitigation of common programming errors forces validation of all inputs before they are trusted.

none

Regular automated validation of system software and data content, combined with scanning of all inbound files, enforces input validation at the boundary before untrusted content is processed.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

RHEL 8 (1 rule)
  • V-230265 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-20

References