# CVE-2018-20168: Denial of service in n/a

> Attackers can cause a denial of service in gVisor via a crafted application due to improper pagetable reuse, requiring an upgrade to fix.

- **Severity:** Medium 5.5 (`CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 17 Dec 2018
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-7rr2-q546-7grq

## What is CVE-2018-20168?

CVE-2018-20168 is a medium-severity denial of service vulnerability in n/a, published on 17 Dec 2018. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

Google gVisor before 2018-08-22 reuses a pagetable in a different level with the paging-structure cache intact, which allows attackers to cause a denial of service ("physical address not valid" panic) via a crafted application.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2018-20168?

It affects 1 product.


Products: Google Gvisor.

## How do I fix CVE-2018-20168?

No fix has been published for CVE-2018-20168 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-20168 being exploited?

There is no known exploitation of CVE-2018-20168 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2018-19333](https://insights.sbomify.com/CVE-2018-19333/): Use after free in n/a (critical 9.8)
- [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)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-20168 and fix it if it is affected.

What it is: CVE-2018-20168 is a medium-severity denial of service vulnerability in n/a, published on 17 Dec 2018. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2018-20168 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-2018-20168/ (Markdown: https://insights.sbomify.com/CVE-2018-20168/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-20168
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-20168
- OSV: https://osv.dev/vulnerability/CVE-2018-20168

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-20168/
Summaries are generated and may contain mistakes; the official description above is the record.