# CVE-2018-19333: Use after free in n/a

> Attackers can overwrite memory in root processes within gVisor sandboxes due to mishandled reference counting in shared memory operations.

- **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:** No
- **Published:** 17 Nov 2018
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-r6hh-xg5m-g342

## What is CVE-2018-19333?

CVE-2018-19333 is a critical use after free vulnerability in n/a, published on 17 Nov 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

pkg/sentry/kernel/shm/shm.go in Google gVisor before 2018-11-01 allows attackers to overwrite memory locations in processes running as root (but not escape the sandbox) via vectors involving IPC_RMID shmctl calls, because reference counting is mishandled.

## Which versions are affected by CVE-2018-19333?

It affects 1 product.


Products: Google Gvisor.

## How do I fix CVE-2018-19333?

No fix has been published for CVE-2018-19333 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-19333 being exploited?

There is no known exploitation of CVE-2018-19333 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2025-2713](https://insights.sbomify.com/CVE-2025-2713/): Improper File Permission Handling in Google gVisor runsc (medium 6.8)
- [CVE-2018-16359](https://insights.sbomify.com/CVE-2018-16359/): Path traversal in n/a (medium 6.8)
- [CVE-2024-10026](https://insights.sbomify.com/CVE-2024-10026/): Improved Seeding and Hashing In gVisor (medium 6.3)
- [CVE-2024-10603](https://insights.sbomify.com/CVE-2024-10603/): Information disclosure in gVisor (medium 6.3)
- [CVE-2018-20168](https://insights.sbomify.com/CVE-2018-20168/): Denial of service in n/a (medium 5.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-19333 and fix it if it is affected.

What it is: CVE-2018-19333 is a critical use after free vulnerability in n/a, published on 17 Nov 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-2018-19333 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-2018-19333/ (Markdown: https://insights.sbomify.com/CVE-2018-19333/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-19333
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-19333
- OSV: https://osv.dev/vulnerability/CVE-2018-19333

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-19333/
Summaries are generated and may contain mistakes; the official description above is the record.