---
id: CVE-2020-1154
title: >-
  An elevation of privilege vulnerability exists when the Windows Common Log
  File System (CLFS) driver improperly handles objects in memory
summary: >-
  An elevation of privilege vulnerability exists when the Windows Common Log
  File System (CLFS) driver improperly handles objects in memory. An attacker
  who successfully exploited this vulnerability could run processes in an
  elevated conte…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
vendor: microsoft
product: windows_10
affected:
  - windows_10
  - windows_10 = 1607
  - windows_10 = 1709
  - windows_10 = 1803
  - windows_10 = 1809
  - windows_10 = 1903
  - windows_10 = 1909
  - windows_7
  - windows_8.1
  - windows_rt_8.1
  - windows_server_2008
  - windows_server_2008 = r2
  - windows_server_2012
  - windows_server_2012 = r2
  - windows_server_2016
  - windows_server_2016 = 1803
  - windows_server_2016 = 1903
  - windows_server_2016 = 1909
  - windows_server_2019
published: '2020-05-21'
updated: '2026-08-19'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2020-1154'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2020-1154'
    label: secure@microsoft.com
  - url: >-
      https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1154
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00944
epssPercentile: 0.59432
ingestedAt: '2026-08-19T17:42:39.660Z'
---

## Overview

An elevation of privilege vulnerability exists when the Windows Common Log File System (CLFS) driver improperly handles objects in memory. An attacker who successfully exploited this vulnerability could run processes in an elevated context.
To exploit the vulnerability, an attacker would first have to log on to the system, and then run a specially crafted application to take control over the affected system.
The security update addresses the vulnerability by correcting how CLFS handles objects in memory.

## Affected

- `windows_10`
- `windows_10 = 1607`
- `windows_10 = 1709`
- `windows_10 = 1803`
- `windows_10 = 1809`
- `windows_10 = 1903`
- `windows_10 = 1909`
- `windows_7`
- `windows_8.1`
- `windows_rt_8.1`
- `windows_server_2008`
- `windows_server_2008 = r2`
- `windows_server_2012`
- `windows_server_2012 = r2`
- `windows_server_2016`
- `windows_server_2016 = 1803`
- `windows_server_2016 = 1903`
- `windows_server_2016 = 1909`
- `windows_server_2019`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.