# CVE-2021-46873: Race condition in n/a

> An attacker can permanently disable a WireGuard private key by manipulating system time via unauthenticated NTP, causing a denial of service.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 29 Jan 2023
- **Updated:** 28 Mar 2025
- **Also known as:** GHSA-mv36-8276-2729, UBUNTU-CVE-2021-46873

## What is CVE-2021-46873?

CVE-2021-46873 is a medium-severity vulnerability in n/a, published on 29 Jan 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

WireGuard, such as WireGuard 0.5.3 on Windows, does not fully account for the possibility that an adversary might be able to set a victim's system time to a future value, e.g., because unauthenticated NTP is used. This can lead to an outcome in which one static private key becomes permanently useless.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2021-46873?

It affects 1 product.


Products: Wireguard Wireguard.

## How do I fix CVE-2021-46873?

No fix has been published for CVE-2021-46873 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-46873 being exploited?

There is no known exploitation of CVE-2021-46873 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2023-35838](https://insights.sbomify.com/CVE-2023-35838/): Misconfiguration in n/a (medium 5.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-46873 and fix it if it is affected.

What it is: CVE-2021-46873 is a medium-severity vulnerability in n/a, published on 29 Jan 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-46873 in the wild and no public exploit code.

Affected product: n/a. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2021-46873/ (Markdown: https://insights.sbomify.com/CVE-2021-46873/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-46873
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-46873
- OSV: https://osv.dev/vulnerability/CVE-2021-46873

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-46873/
Summaries are generated and may contain mistakes; the official description above is the record.