CVE-2021-33783: Windows SMB Information Disclosure Vulnerability

Published Jul 13, 2021
·
Updated

Windows SMB Information Disclosure Vulnerability

Affected Software

57 affected componentsFixes available
Microsoft Windows 10
Microsoft Windows 10=20h2
Microsoft Windows 10=21h1
Microsoft Windows 10=1607
Microsoft Windows 10=1809
Microsoft Windows 10=1909
Microsoft Windows 10=2004
Microsoft Windows 7=sp1
Microsoft Windows 8.1
Microsoft Windows RT 8.1
Microsoft Windows Server 2008=sp1
Microsoft Windows Server 2008=sp2
Microsoft Windows Server 2012
Microsoft Windows Server 2012=r2
Microsoft Windows Server 2016
Microsoft Windows Server 2016=20h2
Microsoft Windows Server 2016=2004
Microsoft Windows Server 2019
Microsoft Windows Server 2008 R2<6.1.7601.25661
6.1.7601.25661
Microsoft Windows Server 2012<6.2.9200.23409
6.2.9200.23409
Microsoft Windows Server 2012<6.2.9200.23409
6.2.9200.23409
Microsoft Windows Server 2008 R2<6.1.7601.25661
6.1.7601.25661
Microsoft Windows Server 2012 R2<6.3.9600.20069
6.3.9600.20069
Microsoft Windows Server 2012 R2<6.3.9600.20069
6.3.9600.20069
Microsoft Windows RT 8.1<6.3.9600.20069
6.3.9600.20069
Microsoft Windows Server 2008<6.0.6003.21167
6.0.6003.21167
Microsoft Windows Server 2008<6.0.6003.21167
6.0.6003.21167
Microsoft Windows Server 2008<6.0.6003.21167
6.0.6003.21167
Microsoft Windows Server 2008<6.0.6003.21167
6.0.6003.21167
Microsoft Windows 8.1 for x64-based systems<6.3.9600.20069
6.3.9600.20069
Microsoft Windows 8.1 for 32-bit systems<6.3.9600.20069
6.3.9600.20069
Microsoft Windows 7<6.1.7601.25661
6.1.7601.25661
Microsoft Windows Server 2016<10.0.14393.4530
10.0.14393.4530
Microsoft Windows 7<6.1.7601.25661
6.1.7601.25661
Microsoft Windows Server 2016<10.0.14393.4530
10.0.14393.4530
Microsoft Windows 10=1607
10.0.14393.4530
Microsoft Windows 10<10.0.10240.19003
10.0.10240.19003
Microsoft Windows 10<10.0.10240.19003
10.0.10240.19003
Microsoft Windows Server=20H2
10.0.19042.1110
Microsoft Windows 10=20H2
10.0.19042.1110
Microsoft Windows 10=20H2
10.0.19042.1110
Microsoft Windows 10=1607
10.0.14393.4530
Microsoft Windows Server=2004
10.0.19041.1110
Microsoft Windows 10=2004
10.0.19041.1110
Microsoft Windows 10=2004
10.0.19041.1110
Microsoft Windows 10=2004
10.0.19041.1110
Microsoft Windows 10=1909
10.0.18363.1679
Microsoft Windows 10=1909
10.0.18363.1679
Microsoft Windows 10=21H1
10.0.19043.1110
Microsoft Windows 10=21H1
10.0.19043.1110
Microsoft Windows 10=21H1
10.0.19043.1110
Microsoft Windows Server 2019<10.0.17763.2061
10.0.17763.2061
Microsoft Windows Server 2019<10.0.17763.2061
10.0.17763.2061
Microsoft Windows 10=1909
10.0.18363.1679
Microsoft Windows 10=1809
10.0.17763.2061
Microsoft Windows 10=1809
10.0.17763.2061
Microsoft Windows 10=1809
10.0.17763.2061

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 6.1.7601.25661Patch KB5004307
  2. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 6.2.9200.23409Patch KB5004302
  3. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 6.3.9600.20069Patch KB5004285
  4. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 6.3.9600.20069Patch KB5004298
  5. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 6.0.6003.21167Patch KB5004299
  6. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.14393.4530Patch KB5004238
  7. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.10240.19003Patch KB5004249
  8. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.19042.1110Patch KB5004237
  9. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.19041.1110Patch KB5004237
  10. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.18363.1679Patch KB5004245
  11. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.19043.1110Patch KB5004237
  12. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.17763.2061Patch KB5004244

Event History

Jul 13, 2021
CVE Published
via Microsoft·02:00 PM
Data Sourced
via Microsoft·02:00 PM
DescriptionSeverityWeaknessAffected Software
Updated
via Microsoft·02:00 PM
Affected Software
Updated
via Microsoft·02:00 PM
Description
Jul 14, 2021
CVE Published
via MITRE·05:53 PM
Data Sourced
via MITRE·05:53 PM
DescriptionSeverity
Data Sourced
via NVD·06:15 PM
RemedyDescriptionSeverityAffected Software

Frequently Asked Questions

1

What is the severity of CVE-2021-33783?

CVE-2021-33783 has a severity rating of High as it allows information disclosure via the Windows SMB service.

2

How do I fix CVE-2021-33783?

To fix CVE-2021-33783, apply the security updates provided by Microsoft for the affected versions of Windows.

3

What systems are affected by CVE-2021-33783?

CVE-2021-33783 affects multiple versions of Microsoft Windows, including Windows 10, Windows 7, Windows 8.1, and various Windows Server editions.

4

What type of vulnerability is CVE-2021-33783?

CVE-2021-33783 is classified as an Information Disclosure vulnerability in the Windows SMB service.

5

Is CVE-2021-33783 being actively exploited?

There is potential for CVE-2021-33783 to be exploited, making it crucial for users to apply patches promptly.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203