# CVE-2021-4327: SerenityOS TypedArray.cpp initialize_typed_array_from_array_buffer integer overflow

> An integer overflow in SerenityOS's JavaScript engine allows attackers to potentially execute arbitrary code or escalate privileges.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 1 Mar 2023
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-mh6x-wxv2-qm6f

## What is CVE-2021-4327?

CVE-2021-4327 is a medium-severity vulnerability in SerenityOS, published on 1 Mar 2023. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability was found in SerenityOS. It has been rated as critical. Affected by this issue is the function initialize_typed_array_from_array_buffer in the library Userland/Libraries/LibJS/Runtime/TypedArray.cpp. The manipulation leads to integer overflow. The exploit has been disclosed to the public and may be used. Continious delivery with rolling releases is used by this product. Therefore, no version details of affected nor updated releases are available. The patch is identified as f6c6047e49f1517778f5565681fb64750b14bf60. It is recommended to apply a patch to fix this issue. VDB-222074 is the identifier assigned to this vulnerability.

Weakness: CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2021-4327?

It affects 1 product.


Products: Serenityos Serenityos.

## How do I fix CVE-2021-4327?

No fix has been published for CVE-2021-4327 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-4327 being exploited?

There is no known exploitation of CVE-2021-4327 in the wild and no public exploit code.

## Other vulnerabilities in SerenityOS

- [CVE-2021-31272](https://insights.sbomify.com/CVE-2021-31272/): Path traversal in n/a (critical 9.8)
- [CVE-2021-30045](https://insights.sbomify.com/CVE-2021-30045/): Memory corruption in n/a (critical 9.1)
- [CVE-2021-28874](https://insights.sbomify.com/CVE-2021-28874/): Memory corruption in n/a (high 7.8)
- [CVE-2019-20172](https://insights.sbomify.com/CVE-2019-20172/): Privilege escalation in n/a (high 7.8)
- [CVE-2021-33185](https://insights.sbomify.com/CVE-2021-33185/): Memory corruption in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-4327 and fix it if it is affected.

What it is: CVE-2021-4327 is a medium-severity vulnerability in SerenityOS, published on 1 Mar 2023. 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-2021-4327 in the wild and no public exploit code.

Affected product: SerenityOS. 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-2021-4327/ (Markdown: https://insights.sbomify.com/CVE-2021-4327/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-4327
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-4327
- OSV: https://osv.dev/vulnerability/CVE-2021-4327

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-4327/
Summaries are generated and may contain mistakes; the official description above is the record.