Important CVSS 5.5 EPSS 0.01454 2020-02 archive

Executive Summary

An information disclosure vulnerability exists in the Windows Common Log File System (CLFS) driver when it fails to properly handle objects in memory. An attacker who successfully exploited this vulnerability could potentially read data that was not intended to be disclosed. Note that this vulnerability would not allow an attacker to execute code or to elevate their user rights directly, but it could be used to obtain information that could be used to try to further compromise the affected system. 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.

Overview

5.5
CVSS MEDIUM
Important
MS Severity
Not Exploited
MS Exploit Status
More Likely
MS Exploit Likelihood
Category Information Disclosure
Released Feb 11 2020
Last Updated Feb 11 2020
Publicly Disclosed No
CISA KEV Not Listed
Known Exploits None Known
EPSS Score 0.01454 — 0.70022 percentile
NVD CVSS 5.5 MEDIUM — matches MSRC

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C
ATTACK VECTOR
Local
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
Low
USER INTERACTION
None
SCOPE
Unchanged
CONFIDENTIALITY
High
INTEGRITY
None
AVAILABILITY
None
EXPLOIT CODE MATURITY
Proof-of-Concept
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 5.0

EPSS Score

0.01454
probability of exploitation in the next 30 days
0.70022 percentile - updated 2026-06-21
View on FIRST.org

Affected Products

27 affected products
Product KB Article Severity Impact Restart Required
Windows 10 for 32-bit Systems 4537776 (Security Update) Important Information Disclosure Yes
Windows 10 for x64-based Systems 4537776 (Security Update) Important Information Disclosure Yes
Windows 10 Version 1607 for 32-bit Systems 4537764 (Security Update) Important Information Disclosure Yes
Windows 10 Version 1607 for x64-based Systems 4537764 (Security Update) Important Information Disclosure Yes
Windows 10 Version 1709 for 32-bit Systems 4537789 (Security Update) Important Information Disclosure Yes
Windows 10 Version 1709 for ARM64-based Systems 4537789 (Security Update) Important Information Disclosure Yes
Windows 10 Version 1709 for x64-based Systems 4537789 (Security Update) Important Information Disclosure Yes
Windows 10 Version 1803 for 32-bit Systems 4537762 (Security Update) Important Information Disclosure Yes
Windows 10 Version 1803 for ARM64-based Systems 4537762 (Security Update) Important Information Disclosure Yes
Windows 10 Version 1803 for x64-based Systems 4537762 (Security Update) Important Information Disclosure Yes
Windows 10 Version 1809 for 32-bit Systems 4532691 (Security Update) Important Information Disclosure Yes
Windows 10 Version 1809 for ARM64-based Systems 4532691 (Security Update) Important Information Disclosure Yes
Windows 10 Version 1809 for x64-based Systems 4532691 (Security Update) Important Information Disclosure Yes
Windows 10 Version 1903 for 32-bit Systems 4532693 (Security Update) Important Information Disclosure Yes
Windows 10 Version 1903 for ARM64-based Systems 4532693 (Security Update) Important Information Disclosure Yes
Windows 10 Version 1903 for x64-based Systems 4532693 (Security Update) Important Information Disclosure Yes
Windows 10 Version 1909 for 32-bit Systems 4532693 (Security Update) Important Information Disclosure Yes
Windows 10 Version 1909 for ARM64-based Systems 4532693 (Security Update) Important Information Disclosure Yes
Windows 10 Version 1909 for x64-based Systems 4532693 (Security Update) Important Information Disclosure Yes
Windows 7 for 32-bit Systems Service Pack 1 4537820 (Monthly Rollup) 4537813 (Security Only) Important Information Disclosure 4534310 Base: 5.5 Temporal: 5.0 Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C Yes 4537813 Windows 7 for x64-based Systems Service Pack 1 4537820 (Monthly Rollup) 4537813 (Security Only) Important Information Disclosure 4534310 Base: 5.5 Temporal: 5.0 Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C Yes 4537813 Windows 8.1 for 32-bit systems 4537821 (Monthly Rollup) 4537803 (Security Only) Important Information Disclosure 4534297 Base: 5.5 Temporal: 5.0 Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C Yes 4537821 4537803 4537821 Windows 8.1 for x64-based systems 4537821 (Monthly Rollup) 4537803 (Security Only) Important Information Disclosure 4534297 Base: 5.5 Temporal: 5.0 Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C Yes 4537821 4537803 4537821 Windows RT 8.1 4537821 (Monthly Rollup) Important Information Disclosure Yes
Windows Server 2008 for 32-bit Systems Service Pack 2 4537810 (Monthly Rollup) 4537822 (Security Only) Important Information Disclosure 4534303 Base: 5.5 Temporal: 5.0 Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C Yes None Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation) 4537810 (Monthly Rollup) 4537822 (Security Only) Important Information Disclosure 4534303 Base: 5.5 Temporal: 5.0 Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C Yes None Windows Server 2008 for x64-based Systems Service Pack 2 4537810 (Monthly Rollup) 4537822 (Security Only) Important Information Disclosure 4534303 Base: 5.5 Temporal: 5.0 Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C Yes None Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation) 4537810 (Monthly Rollup) 4537822 (Security Only) Important Information Disclosure 4534303 Base: 5.5 Temporal: 5.0 Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C Yes None Windows Server 2008 R2 for x64-based Systems Service Pack 1 4537820 (Monthly Rollup) 4537813 (Security Only) Important Information Disclosure 4534310 Base: 5.5 Temporal: 5.0 Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C Yes 4537813 Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) 4537820 (Monthly Rollup) 4537813 (Security Only) Important Information Disclosure 4534310 Base: 5.5 Temporal: 5.0 Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C Yes 4537813 Windows Server 2012 4537814 (Monthly Rollup) 4537794 (Security Only) Important Information Disclosure 4534283 Base: 5.5 Temporal: 5.0 Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C Yes 4537814 4537794 Windows Server 2012 (Server Core installation) 4537814 (Monthly Rollup) 4537794 (Security Only) Important Information Disclosure 4534283 Base: 5.5 Temporal: 5.0 Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C Yes 4537814 4537794 Windows Server 2012 R2 4537821 (Monthly Rollup) 4537803 (Security Only) Important Information Disclosure 4534297 Base: 5.5 Temporal: 5.0 Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C Yes 4537821 4537803 4537821 Windows Server 2012 R2 (Server Core installation) 4537821 (Monthly Rollup) 4537803 (Security Only) Important Information Disclosure 4534297 Base: 5.5 Temporal: 5.0 Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C Yes 4537821 4537803 4537821 Windows Server 2016 4537764 (Security Update) Important Information Disclosure Yes
Windows Server 2016 (Server Core installation) 4537764 (Security Update) Important Information Disclosure Yes
Windows Server 2019 4532691 (Security Update) Important Information Disclosure Yes
Windows Server 2019 (Server Core installation) 4532691 (Security Update) Important Information Disclosure Yes
Windows Server, version 1803 (Server Core Installation) 4537762 (Security Update) Important Information Disclosure Yes
Windows Server, version 1903 (Server Core installation) 4532693 (Security Update) Important Information Disclosure Yes
Windows Server, version 1909 (Server Core installation) 4532693 (Security Update) Important Information Disclosure Yes

Patches

7 patches
Article Type Restart
4537776 Security Update Yes
4537764 Security Update Yes
4537789 Security Update Yes
4537762 Security Update Yes
4532691 Security Update Yes
4532693 Security Update Yes
4537821 Monthly Rollup Yes

Known Exploits

Acknowledgments

None