CVE-2021-1638
Windows Bluetooth Security Feature Bypass Vulnerability
Microsoft is aware of the "Impersonation in the Passkey Entry Protocol" vulnerability. For more information regarding the vulnerability, please see this statement from the Bluetooth SIG. To address the vulnerability, Microsoft has released a software update that will fail attempts to pair if the remote device exchanges a public key with the same X coordinate as the locally exchanged public key
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Windows Bluetooth Security Feature Bypass Vulnerability
Microsoft is aware of the "Impersonation in the Passkey Entry Protocol" vulnerability. For more information regarding the vulnerability, please see this statement from the Bluetooth SIG. To address the vulnerability, Microsoft has released a software update that will fail attempts to pair if the remote device exchanges a public key with the same X coordinate as the locally exchanged public key
- Record
CVE-2021-1638- CVSS 3.1
- 7.7 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C - Updated
- 2026-11-02
EUVDEUVD-2021-7105
Microsoft is aware of the "Impersonation in the Passkey Entry Protocol" vulnerability. For more information regarding the vulnerability, please see this statement from the Bluetooth SIG. To address the vulnerability, Microsoft has released a software update that will fail attempts to pair if the remote device exchanges a public key with the same X coordinate as the locally exchanged public key
- Record
EUVD-2021-7105- CVSS 3.1
- 7.7 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-j3p8-mm22-v647
Windows Bluetooth Security Feature Bypass Vulnerability This CVE ID is unique from CVE-2021-1683,...
Windows Bluetooth Security Feature Bypass Vulnerability This CVE ID is unique from CVE-2021-1683, CVE-2021-1684.
- Record
GHSA-j3p8-mm22-v647- CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-863
- Updated
- 2026-11-02
NVD
Microsoft is aware of the "Impersonation in the Passkey Entry Protocol" vulnerability. For more information regarding the vulnerability, please see this statement from the Bluetooth SIG. To address the vulnerability, Microsoft has released a software update that will fail attempts to pair if the remote device exchanges a public key with the same X coordinate as the locally exchanged public key
- Record
CVE-2021-1638- CVSS 3.1
- 7.7 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N - CVSS 2.0
- 2.1 Low
AV:L/AC:L/Au:N/C:P/I:N/A:N - Updated
- 2026-11-02
Affected products
- microsoft windows 10 version 1803
- microsoft windows 10 version 1809
- microsoft windows 10 version 1909
- microsoft windows 10 version 2004
- microsoft windows 10 version 20h2
- microsoft windows server 2019
- microsoft windows server 2019 (server core installation)
- microsoft windows server version 2004
- microsoft windows server version 20h2
- microsoft windows server, version 1909 (server core installation)
- microsoft windows 10
- microsoft windows server 2016
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-1638 is a high vulnerability (CVSS 7.7) in Microsoft Windows 10 Version 1803, published January 12, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.23%, the 69th percentile. No source names a fixed version.