# CVE-2016-9381: Race condition in n/a

> Local guest administrators can escalate privileges via a double fetch race condition in QEMU shared rings.

- **Severity:** High 7.5 (`CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 23 Jan 2017
- **Updated:** 6 Aug 2024
- **Also known as:** ALPINE-CVE-2016-9381, DEBIAN-CVE-2016-9381, GHSA-fg67-6qhp-f8mj, UBUNTU-CVE-2016-9381

## What is CVE-2016-9381?

CVE-2016-9381 is a high-severity vulnerability in Citrix Xenserver, published on 23 Jan 2017. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Race condition in QEMU in Xen allows local x86 HVM guest OS administrators to gain privileges by changing certain data on shared rings, aka a "double fetch" vulnerability.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2016-9381?

It affects 2 products.


Products: Citrix Xenserver, Qemu Qemu.

## How do I fix CVE-2016-9381?

Apply the vendor's patch.

## Is CVE-2016-9381 being exploited?

There is no known exploitation of CVE-2016-9381 in the wild and no public exploit code.

## Other vulnerabilities in Citrix Xenserver

- [CVE-2014-4947](https://insights.sbomify.com/CVE-2014-4947/): Memory corruption in n/a (critical 10.0)
- [CVE-2018-14007](https://insights.sbomify.com/CVE-2018-14007/): Path traversal in n/a (critical 9.8)
- [CVE-2015-7705](https://insights.sbomify.com/CVE-2015-7705/): Denial of service in n/a (critical 9.8)
- [CVE-2016-5302](https://insights.sbomify.com/CVE-2016-5302/): Auth bypass in n/a (critical 9.8)
- [CVE-2017-12134](https://insights.sbomify.com/CVE-2017-12134/): Memory corruption in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-9381 and fix it if it is affected.

What it is: CVE-2016-9381 is a high-severity vulnerability in Citrix Xenserver, published on 23 Jan 2017. 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-2016-9381 in the wild and no public exploit code.

Affected product: Citrix Xenserver. 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-2016-9381/ (Markdown: https://insights.sbomify.com/CVE-2016-9381/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-9381
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-9381
- OSV: https://osv.dev/vulnerability/CVE-2016-9381

---
From sbomify Insights: https://insights.sbomify.com/CVE-2016-9381/
Summaries are generated and may contain mistakes; the official description above is the record.