CVE-2021-38636: Windows Redirected Drive Buffering SubSystem Driver Information Disclosure Vulnerability

Severity: low (CVSS 2.1 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-09-15 · updated 2026-08-10

Description

Windows Redirected Drive Buffering SubSystem Driver Information Disclosure Vulnerability

Affected products

Microsoft Windows 10 Version 1607: 20h2, 21h1, 1607, 1809, 1909, 2004
Microsoft Windows 7: all versions
Microsoft Windows 8.1: all versions
Microsoft Windows RT 8.1: all versions
Microsoft Windows Server 2008: r2-sp1
Microsoft Windows Server 2012: all versions
Microsoft Windows Server 2016: 20h2, 2004
Microsoft Windows Server 2019: all versions
Microsoft Windows Server 2022: all versions
Microsoft Windows 10 Version 1507: from 10.0.10240.0 before 10.0.10240.19060 — fixed in 10.0.10240.19060
Microsoft Windows 10 1607: from 10.0.14393.0 before 10.0.14393.4651 — fixed in 10.0.14393.4651
Microsoft Windows 10: from 10.0.17763.0 before 10.0.17763.2183 — fixed in 10.0.17763.2183
Microsoft Windows 10 1909: from 10.0.0 before 10.0.18363.1801 — fixed in 10.0.18363.1801
Microsoft Windows 10 2004: from 10.0.0 before 10.0.19041.1237 — fixed in 10.0.19041.1237
Microsoft Windows 10 20H2: from 10.0.0 before 10.0.19042.1237 — fixed in 10.0.19042.1237
Microsoft Windows 10 21H1: from 10.0.0 before 10.0.19043.1237 — fixed in 10.0.19043.1237
Microsoft Windows 7: from 6.1.0 before 6.1.7601.25712 — fixed in 6.1.7601.25712
Microsoft Windows 7 Service Pack 1: from 6.1.0 before 6.1.7601.25712 — fixed in 6.1.7601.25712
Microsoft Windows 8.1: from 6.3.0 before 6.3.9600.20120 — fixed in 6.3.9600.20120
Microsoft Windows Server 2008 R2 Service Pack 1: from 6.1.7601.0 before 6.1.7601.25712 — fixed in 6.1.7601.25712
Microsoft Windows Server 2008 Service Pack 2: from 6.0.6003.0 before 6.0.6003.21218 — fixed in 6.0.6003.21218
Microsoft Windows Server 2012: from 6.2.9200.0 before 6.2.9200.23462 — fixed in 6.2.9200.23462
Microsoft Windows Server 2012 R2: from 6.3.9600.0 before 6.3.9600.20120 — fixed in 6.3.9600.20120
Microsoft Windows Server 2016: from 10.0.14393.0 before 10.0.14393.4651 — fixed in 10.0.14393.4651
Microsoft Windows Server 2019: from 10.0.17763.0 before 10.0.17763.2183 — fixed in 10.0.17763.2183
Microsoft Windows Server 2022: from 10.0.20348.0 before 10.0.20348.230 — fixed in 10.0.20348.230
Microsoft Windows Server version 2004: from 10.0.0 before 10.0.19041.1237 — fixed in 10.0.19041.1237
Microsoft Windows Server version 20H2: from 10.0.0 before 10.0.19042.1237 — fixed in 10.0.19042.1237

How to fix

Upgrade to a fixed version: Microsoft Windows 10 Version 1507 10.0.10240.19060; Microsoft Windows 10 1607 10.0.14393.4651; Microsoft Windows 10 10.0.17763.2183; Microsoft Windows 10 1909 10.0.18363.1801; Microsoft Windows 10 2004 10.0.19041.1237; Microsoft Windows 10 20H2 10.0.19042.1237; Microsoft Windows 10 21H1 10.0.19043.1237; Microsoft Windows 7 6.1.7601.25712; Microsoft Windows 7 Service Pack 1 6.1.7601.25712; Microsoft Windows 8.1 6.3.9600.20120; Microsoft Windows Server 2008 R2 Service Pack 1 6.1.7601.25712; Microsoft Windows Server 2008 Service Pack 2 6.0.6003.21218. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2021-38636 or the next vulnerability affects your stack