# CVE-2018-10199: Use after free in n/a

> An attacker can execute arbitrary code via a use-after-free vulnerability in the mruby library's file initialization function.

- **Severity:** Critical 9.8 (`CVSS:3.0/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:** 18 Apr 2018
- **Updated:** 16 Sep 2024
- **Also known as:** DEBIAN-CVE-2018-10199, GHSA-xpq9-m45f-g29q, UBUNTU-CVE-2018-10199

## What is CVE-2018-10199?

CVE-2018-10199 is a critical use after free vulnerability in n/a, published on 18 Apr 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In versions of mruby up to and including 1.4.0, a use-after-free vulnerability exists in src/io.c::File#initilialize_copy(). An attacker that can cause Ruby code to be run can possibly use this to execute arbitrary code.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2018-10199?

It affects 1 product.


Products: Mruby Mruby.

## How do I fix CVE-2018-10199?

Upgrade to a fixed version.

## Is CVE-2018-10199 being exploited?

There is no known exploitation of CVE-2018-10199 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2020-6838](https://insights.sbomify.com/CVE-2020-6838/): Use after free in n/a (critical 9.8)
- [CVE-2020-6839](https://insights.sbomify.com/CVE-2020-6839/): Memory corruption in n/a (critical 9.8)
- [CVE-2020-6840](https://insights.sbomify.com/CVE-2020-6840/): Use after free in n/a (critical 9.8)
- [CVE-2022-1212](https://insights.sbomify.com/CVE-2022-1212/): Use-After-Free in str_escape in mruby/mruby in mruby/mruby (critical 9.3)
- [CVE-2021-4110](https://insights.sbomify.com/CVE-2021-4110/): NULL Pointer Dereference in mruby/mruby (critical 9.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-10199 and fix it if it is affected.

What it is: CVE-2018-10199 is a critical use after free vulnerability in n/a, published on 18 Apr 2018. 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-2018-10199 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-2018-10199/ (Markdown: https://insights.sbomify.com/CVE-2018-10199/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-10199
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-10199
- OSV: https://osv.dev/vulnerability/CVE-2018-10199

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-10199/
Summaries are generated and may contain mistakes; the official description above is the record.