CVE-2020-11005
Internal NCryptDecrypt method could be used externally from WindowsHello library.
The WindowsHello open source library (NuGet HaemmerElectronics.SeppPenner.WindowsHello), before version 1.0.4, has a vulnerability where encrypted data could potentially be decrypted without needing authentication. If the library is used to encrypt text and write the output to a txt file, another executable could be able to decrypt the text using the static method NCryptDecrypt from this same library without the need to use Windows Hello Authentication again. This has been patched in version 1.0.4.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Internal NCryptDecrypt method could be used externally from WindowsHello library.
The WindowsHello open source library (NuGet HaemmerElectronics.SeppPenner.WindowsHello), before version 1.0.4, has a vulnerability where encrypted data could potentially be decrypted without needing authentication. If the library is used to encrypt text and write the output to a txt file, another executable could be able to decrypt the text using the static method NCryptDecrypt from this same library without the need to use Windows Hello Authentication again. This has been patched in version 1.0.4.
- Record
CVE-2020-11005- CVSS 3.1
- 5.1 Medium
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-288
- Updated
- 2026-11-02
EUVDEUVD-2020-0397
The WindowsHello open source library (NuGet HaemmerElectronics.SeppPenner.WindowsHello), before version 1.0.4, has a vulnerability where encrypted data could potentially be decrypted without needing authentication. If the library is used to encrypt text and write the output to a txt file, another executable could be able to decrypt the text using the static method NCryptDecrypt from this same library without the need to use Windows Hello Authentication again. This has been patched in version 1.0.4.
- Record
EUVD-2020-0397- CVSS 3.1
- 5.1 Medium
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-wvpv-ffcv-r6cw
Internal NCryptDecrypt method could be used externally from WindowsHello library.
Impact
Every user of the library before version 1.0.4.
Patches
Patched in 1.0.4+.
Workarounds
None.
References
https://github.com/SeppPenner/WindowsHello/issues/3
For more information
It this library is used to encrypt text and write the output to a txt file, another executable could be able to decrypt the text using the static method NCryptDecrypt from this same library without the need to use Windows Hello Authentication again.
- Record
GHSA-wvpv-ffcv-r6cw- CVSS 3.1
- 5.1 Medium
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-288
- Updated
- 2026-11-02
NVD
The WindowsHello open source library (NuGet HaemmerElectronics.SeppPenner.WindowsHello), before version 1.0.4, has a vulnerability where encrypted data could potentially be decrypted without needing authentication. If the library is used to encrypt text and write the output to a txt file, another executable could be able to decrypt the text using the static method NCryptDecrypt from this same library without the need to use Windows Hello Authentication again. This has been patched in version 1.0.4.
- Record
CVE-2020-11005- CVSS 3.1
- 5.1 Medium
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:N/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 - Weakness
- CWE-288, CWE-327
- Updated
- 2026-11-02
OSV
The WindowsHello open source library (NuGet HaemmerElectronics.SeppPenner.WindowsHello), before version 1.0.4, has a vulnerability where encrypted data could potentially be decrypted without needing authentication. If the library is used to encrypt text and write the output to a txt file, another executable could be able to decrypt the text using the static method NCryptDecrypt from this same library without the need to use Windows Hello Authentication again. This has been patched in version 1.0.4.
- Record
CVE-2020-11005- 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 - Updated
- 2026-11-02
OSVGHSA-wvpv-ffcv-r6cw
Internal NCryptDecrypt method could be used externally from WindowsHello library.
Impact
Every user of the library before version 1.0.4.
Patches
Patched in 1.0.4+.
Workarounds
None.
References
https://github.com/SeppPenner/WindowsHello/issues/3
For more information
It this library is used to encrypt text and write the output to a txt file, another executable could be able to decrypt the text using the static method NCryptDecrypt from this same library without the need to use Windows Hello Authentication again.
- Record
GHSA-wvpv-ffcv-r6cw- CVSS 3.1
- 5.1 Medium
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-288
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
HaemmerElectronics.SeppPenner.WindowsHelloNuGet |
before 1.0.4 | 1.0.4 |
HaemmerElectronics.SeppPenner.WindowsHelloNuGet |
before 1.0.4, plus listed versions 1.0.01.0.0.11.0.21.0.3 |
1.0.4 |
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-11005 is a medium vulnerability (CVSS 5.1) in Sepppenner Windowshello, published April 14, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.23%, the 14th percentile. Fixed in HaemmerElectronics.SeppPenner.WindowsHello 1.0.4.