# CVE-2018-9862: Privilege escalation in n/a

> Attackers can gain root access in Docker containers by exploiting numeric username handling in runV via docker exec.

- **Severity:** High 7.8 (`CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** 9 Apr 2018
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-xpc5-66vp-j2wh

## What is CVE-2018-9862?

CVE-2018-9862 is a high-severity vulnerability in n/a, published on 9 Apr 2018. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

util.c in runV 1.0.0 for Docker mishandles a numeric username, which allows attackers to obtain root access by leveraging the presence of an initial numeric value on an /etc/passwd line, and then issuing a "docker exec" command with that value in the -u argument, a similar issue to CVE-2016-3697.

Weakness: CWE-838 (Inappropriate Encoding for Output Context)

## Which versions are affected by CVE-2018-9862?

It affects 1 product.


Products: Hyper Runv.

## How do I fix CVE-2018-9862?

No fix has been published for CVE-2018-9862 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-9862 being exploited?

There is no known exploitation of CVE-2018-9862 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-9862 and fix it if it is affected.

What it is: CVE-2018-9862 is a high-severity vulnerability in n/a, published on 9 Apr 2018. 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-2018-9862 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-2018-9862/ (Markdown: https://insights.sbomify.com/CVE-2018-9862/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-9862
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-9862
- OSV: https://osv.dev/vulnerability/CVE-2018-9862

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-9862/
Summaries are generated and may contain mistakes; the official description above is the record.