# CVE-2020-11005: Internal NCryptDecrypt method could be used externally from WindowsHello library.

> Attackers can bypass Windows Hello authentication to decrypt sensitive data using an exposed internal method in the WindowsHello library.

- **Severity:** Medium 5.1 (`CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 14 Apr 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-wvpv-ffcv-r6cw

## What is CVE-2020-11005?

CVE-2020-11005 is a medium-severity vulnerability in SeppPenner WindowsHello, published on 14 Apr 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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.

Weakness: CWE-327 (Use of a Broken or Risky Cryptographic Algorithm), CWE-288 (Authentication Bypass Using an Alternate Path or Channel)

## Which versions are affected by CVE-2020-11005?

2 open source packages ship an affected version, including HaemmerElectronics.SeppPenner.WindowsHello. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `HaemmerElectronics.SeppPenner.WindowsHello` | NuGet | All versions | 1.0.4 |
| `HaemmerElectronics.SeppPenner.WindowsHello` | NuGet | All versions | 1.0.4 |

Products: Windowshello Project Windowshello.

## How do I fix CVE-2020-11005?

Upgrade HaemmerElectronics.SeppPenner.WindowsHello to 1.0.4 or later.

## Is CVE-2020-11005 being exploited?

There is no known exploitation of CVE-2020-11005 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-11005 and fix it if it is affected.

What it is: CVE-2020-11005 is a medium-severity vulnerability in SeppPenner WindowsHello, published on 14 Apr 2020. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-11005 in the wild and no public exploit code.

Affected packages and fixed versions:
- HaemmerElectronics.SeppPenner.WindowsHello (NuGet): affected all versions; fixed in 1.0.4
- HaemmerElectronics.SeppPenner.WindowsHello (NuGet): affected all versions; fixed in 1.0.4

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2020-11005/ (Markdown: https://insights.sbomify.com/CVE-2020-11005/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-11005
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-11005
- OSV: https://osv.dev/vulnerability/CVE-2020-11005

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-11005/
Summaries are generated and may contain mistakes; the official description above is the record.