# CVE-2021-25901: Out of bounds read in lazy-init

> A missing Send bound in the lazy-init crate allows data races, potentially leading to memory corruption or crashes in Rust applications.

- **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:** Yes
- **Published:** 22 Jan 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-w47j-hqpf-qw9w, RUSTSEC-2021-0004

## What is CVE-2021-25901?

CVE-2021-25901 is a medium-severity vulnerability in n/a, published on 22 Jan 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An issue was discovered in the lazy-init crate through 2021-01-17 for Rust. Lazy lacks a Send bound, leading to a data race.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2021-25901?

3 open source packages ship an affected version, including lazy-init. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `lazy-init` | crates.io | All versions | 0.4.0 |
| `lazy-init` | crates.io | All versions | 0.4.0 |
| `lazy-init` | crates.io | From 0.0.0-0 | 0.4.1-0 |

Products: Lazy-Init Project Lazy-Init.

## How do I fix CVE-2021-25901?

Upgrade lazy-init to a fixed version for your release line: 0.4.0 or 0.4.1-0.

## Is CVE-2021-25901 being exploited?

There is no known exploitation of CVE-2021-25901 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-25901 and fix it if it is affected.

What it is: CVE-2021-25901 is a medium-severity vulnerability in n/a, published on 22 Jan 2021. 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-2021-25901 in the wild and no public exploit code.

Affected packages and fixed versions:
- lazy-init (crates.io): affected all versions; fixed in 0.4.0
- lazy-init (crates.io): affected all versions; fixed in 0.4.0
- lazy-init (crates.io): affected from 0.0.0-0; fixed in 0.4.1-0

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-2021-25901/ (Markdown: https://insights.sbomify.com/CVE-2021-25901/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-25901
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-25901
- OSV: https://osv.dev/vulnerability/CVE-2021-25901

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-25901/
Summaries are generated and may contain mistakes; the official description above is the record.