How severe is CVE-2021-1669?

CVE-2021-1669 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-1669 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-1669?

CVE-2021-1669 primarily affects Microsoft Remote Desktop. In total, 15 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-1669?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-1669 published?

CVE-2021-1669 was published on 2021-01-12 and last updated on 2026-06-17.

CVE-2021-1669

CVE-2021-1669 is a high-severity vulnerability in Microsoft Remote Desktop with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 6.5
EPSS exploit prediction: 3% (86th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Microsoft Remote Desktop
Published: 2021-01-12
Last modified: 2026-06-17

Description

Windows Remote Desktop Security Feature Bypass Vulnerability

Frequently asked questions

What is CVE-2021-1669?: Windows Remote Desktop Security Feature Bypass Vulnerability
How severe is CVE-2021-1669?: CVE-2021-1669 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-1669 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-1669?: CVE-2021-1669 primarily affects Microsoft Remote Desktop. In total, 15 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-1669?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-1669 published?: CVE-2021-1669 was published on 2021-01-12 and last updated on 2026-06-17.

References

Affected products (15)

cpe:2.3:a:microsoft:remote_desktop:-:*:*:*:*:-:*:*
cpe:2.3:a:microsoft:remote_desktop:-:*:*:*:*:android:*:*
cpe:2.3:a:microsoft:remote_desktop_client:-:*:*:*:*:windows:*:*
cpe:2.3:o:microsoft:windows_10:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:20h2:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:1607:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:1803:*:*:*:*:*:*:*
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_server_2016:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:20h2:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:1909:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:2004:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2019:-:*:*:*:*:*:*:*

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