# CVE-2021-29931: Double free in arenavec

> A double drop vulnerability in the arenavec Rust crate can lead to memory corruption and potential code execution or denial of service.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 1 Apr 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-955p-rc5h-hg6h

## What is CVE-2021-29931?

CVE-2021-29931 is a high-severity use after free vulnerability in n/a, published on 1 Apr 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 arenavec crate through 2021-01-12 for Rust. A double drop can sometimes occur upon a panic in T::drop().

Weakness: CWE-415 (Double Free)

## Which versions are affected by CVE-2021-29931?

2 open source packages ship an affected version, including arenavec. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `arenavec` | crates.io | All versions to 0.1.1 | None |
| `arenavec` | crates.io | All versions to 0.1.1 | None |

Products: Arenavec Project Arenavec.

## How do I fix CVE-2021-29931?

No fix has been published for CVE-2021-29931 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-29931 being exploited?

There is no known exploitation of CVE-2021-29931 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2021-29930](https://insights.sbomify.com/CVE-2021-29930/): Out of bounds write in arenavec (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-29931 and fix it if it is affected.

What it is: CVE-2021-29931 is a high-severity use after free vulnerability in n/a, published on 1 Apr 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-2021-29931 in the wild and no public exploit code.

Affected packages and fixed versions:
- arenavec (crates.io): affected all versions up to 0.1.1; no fix listed
- arenavec (crates.io): affected all versions up to 0.1.1; no fix listed

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-2021-29931/ (Markdown: https://insights.sbomify.com/CVE-2021-29931/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-29931
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-29931
- OSV: https://osv.dev/vulnerability/CVE-2021-29931

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-29931/
Summaries are generated and may contain mistakes; the official description above is the record.