How severe is CVE-2021-38629?

CVE-2021-38629 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-38629 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-38629?

CVE-2021-38629 primarily affects Microsoft Windows 10. In total, 19 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-38629?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-38629 published?

CVE-2021-38629 was published on 2021-09-15 and last updated on 2026-06-17.

CVE-2021-38629

CVE-2021-38629 is a medium-severity vulnerability in Microsoft Windows 10 with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.0
EPSS exploit prediction: 2% (82nd percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Microsoft Windows 10
Published: 2021-09-15
Last modified: 2026-06-17

Description

Windows Ancillary Function Driver for WinSock Information Disclosure Vulnerability

Frequently asked questions

What is CVE-2021-38629?: Windows Ancillary Function Driver for WinSock Information Disclosure Vulnerability
How severe is CVE-2021-38629?: CVE-2021-38629 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-38629 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-38629?: CVE-2021-38629 primarily affects Microsoft Windows 10. In total, 19 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-38629?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-38629 published?: CVE-2021-38629 was published on 2021-09-15 and last updated on 2026-06-17.

References

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-38629

Affected products (19)

cpe:2.3:o:microsoft:windows_10:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:20h2:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:21h1:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:1607:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:1809:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:1909:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:2004:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_7:-:sp1:*:*:-:*:-:*
cpe:2.3:o:microsoft:windows_8.1:-:*:*:*:-:*:-:*
cpe:2.3:o:microsoft:windows_rt_8.1:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2012:-:r2:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:20h2:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:2004:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2019:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2022:-:*:*:*:*:*:*:*

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