# CVE-2018-15468: Denial of service in n/a

> A malicious guest administrator can lock up the entire host by exploiting unvirtualized Branch Trace Store features when vPMU is disabled.

- **Severity:** Medium 6.0 (`CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/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:** 17 Aug 2018
- **Updated:** 5 Aug 2024
- **Also known as:** ALPINE-CVE-2018-15468, DEBIAN-CVE-2018-15468, GHSA-m48w-fvxv-5j3g, UBUNTU-CVE-2018-15468

## What is CVE-2018-15468?

CVE-2018-15468 is a medium-severity denial of service vulnerability in Xen Xen, published on 17 Aug 2018. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

An issue was discovered in Xen through 4.11.x. The DEBUGCTL MSR contains several debugging features, some of which virtualise cleanly, but some do not. In particular, Branch Trace Store is not virtualised by the processor, and software has to be careful to configure it suitably not to lock up the core. As a result, it must only be available to fully trusted guests. Unfortunately, in the case that vPMU is disabled, all value checking was skipped, allowing the guest to choose any MSR_DEBUGCTL setting it likes. A malicious or buggy guest administrator (on Intel x86 HVM or PVH) can lock up the entire host, causing a Denial of Service.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2018-15468?

It affects 1 product.


Products: Xen Xen.

## How do I fix CVE-2018-15468?

Apply the vendor's patch.

## Is CVE-2018-15468 being exploited?

There is no known exploitation of CVE-2018-15468 in the wild and no public exploit code.

## Other vulnerabilities in Xen Xen

- [CVE-2017-10912](https://insights.sbomify.com/CVE-2017-10912/): Privilege escalation in n/a (critical 10.0)
- [CVE-2017-10918](https://insights.sbomify.com/CVE-2017-10918/): Memory corruption in n/a (critical 10.0)
- [CVE-2017-10920](https://insights.sbomify.com/CVE-2017-10920/): Memory corruption in n/a (critical 10.0)
- [CVE-2017-10921](https://insights.sbomify.com/CVE-2017-10921/): Memory corruption in n/a (critical 10.0)
- [CVE-2025-27466](https://insights.sbomify.com/CVE-2025-27466/): Mutiple vulnerabilities in the Viridian interface (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-15468 and fix it if it is affected.

What it is: CVE-2018-15468 is a medium-severity denial of service vulnerability in Xen Xen, published on 17 Aug 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-2018-15468 in the wild and no public exploit code.

Affected product: Xen Xen. 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-2018-15468/ (Markdown: https://insights.sbomify.com/CVE-2018-15468/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-15468
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-15468
- OSV: https://osv.dev/vulnerability/CVE-2018-15468

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-15468/
Summaries are generated and may contain mistakes; the official description above is the record.