# CVE-2020-36318: Use after free in n/a

> A bug in Rust's VecDeque::make_contiguous can cause use-after-free or double free, potentially leading to code execution or crashes.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 11 Apr 2021
- **Updated:** 4 Aug 2024
- **Also known as:** DEBIAN-CVE-2020-36318, GHSA-w7c8-v5h2-32ff, UBUNTU-CVE-2020-36318

## What is CVE-2020-36318?

CVE-2020-36318 is a critical use after free vulnerability in n/a, published on 11 Apr 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the standard library in Rust before 1.49.0, VecDeque::make_contiguous has a bug that pops the same element more than once under certain condition. This bug could result in a use-after-free or double free.

Weakness: CWE-416 (Use After Free), CWE-415 (Double Free)

## Which versions are affected by CVE-2020-36318?

It affects 1 product.


Products: Rust-Lang Rust.

## How do I fix CVE-2020-36318?

Upgrade to a fixed version.

## Is CVE-2020-36318 being exploited?

There is no known exploitation of CVE-2020-36318 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2018-1000810](https://insights.sbomify.com/CVE-2018-1000810/): Integer overflow in n/a (critical 9.8)
- [CVE-2021-29922](https://insights.sbomify.com/CVE-2021-29922/): Security feature bypass in n/a (critical 9.1)
- [CVE-2024-43402](https://insights.sbomify.com/CVE-2024-43402/): Rust OS Command Injection/Argument Injection vulnerability (high 8.2)
- [CVE-2018-1000657](https://insights.sbomify.com/CVE-2018-1000657/): Memory corruption in n/a (high 7.8)
- [CVE-2018-1000622](https://insights.sbomify.com/CVE-2018-1000622/): Other in n/a (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-36318 and fix it if it is affected.

What it is: CVE-2020-36318 is a critical use after free vulnerability in n/a, published on 11 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-2020-36318 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-2020-36318/ (Markdown: https://insights.sbomify.com/CVE-2020-36318/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-36318
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-36318
- OSV: https://osv.dev/vulnerability/CVE-2020-36318

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-36318/
Summaries are generated and may contain mistakes; the official description above is the record.