CVE-2020-17087

Microsoft Windows Server 2016 1903 … 20h2

CISA KEVActive ExploitationEUVD Exploited

Published

11 November 2020

Modified

29 October 2025

KEV Added

03 November 2021

Patch / advisory

View advisory

CVSS Score v3.1 7.8

Click a component to see what it means

Raw vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Score 0.054 92th percentile

Risk Priority 83 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2020-17087 is a high-severity Incorrect Calculation of Buffer Size (CWE-131) vulnerability in Microsoft Windows Server 2016. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 8% 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.

The vulnerability CVE-2020-17087 is a Windows Kernel Local Elevation of Privilege Vulnerability affecting the Windows kernel. It is associated with CWE-131 and has a CVSS 3.1 score of 7.8 reflecting local attack vector, low attack complexity, and low privileges required.

An attacker with local access and low privileges can exploit the flaw without user interaction to obtain full elevation of privileges, resulting in high impact to confidentiality, integrity, and availability on the affected system.

Microsoft has published security guidance for the issue via its advisory portal, and the vulnerability appears in the CISA catalog of known exploited vulnerabilities.

EU & UK References

🇪🇺 ENISA EUVD: EUVD-2020-9042

Vulnerability Data

Windows Kernel Local Elevation of Privilege Vulnerability

CWE(s): CWE-131
KEV Date Added: 03 November 2021

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation

Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.

attack.mitre.org →

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.

attack.mitre.org →

T1203 Exploitation for Client Execution Execution

Adversaries may exploit software vulnerabilities in client applications to execute code.

attack.mitre.org →

T1210 Exploitation of Remote Services Lateral Movement

Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.

attack.mitre.org →

T1212 Exploitation for Credential Access Credential Access

Adversaries may exploit software vulnerabilities in an attempt to collect credentials.

attack.mitre.org →

Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

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Affected Assets

microsoft

windows 10 1507

all versions

microsoft

windows 10 1607

all versions

microsoft

windows 10 1803

all versions

microsoft

windows 10 1809

all versions

microsoft

windows 10 1903

all versions

microsoft

windows 10 1909

all versions

microsoft

windows 10 2004

all versions

microsoft

windows 10 20h2

all versions

microsoft

windows 7

all versions

microsoft

windows 8.1

all versions

+5 more product configuration(s) — see NVD for full list

Mitigating Controls

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 prevent buffer-size miscalculations via coding standards, reviews, and testing, while fixing this single weakness only partially fulfills the broader control.

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.

A.8.28 Secure coding mostly match

degrades

Secure coding standards directly require correct buffer-size calculations.

A.8.29 Security testing in development and acceptance mostly match

finds

Security testing can detect buffer-size errors before release.

A.8.25 Secure development life cycle partial match

prevents

Secure development lifecycle mandates size-checking practices that reduce buffer-size miscalculations.

A.8.26 Application security requirements partial match

prevents

Application security requirements can specify buffer-size validation rules.