# CVE-2015-4164: Denial of service in n/a

> Local 32-bit PV guest administrators can cause a system hang via a specific hypercall due to a loop iteration error in the Xen hypervisor.

- **Severity:** Medium 4.9 (`AV:L/AC:L/Au:N/C:N/I:N/A:C`)
- **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:** 15 Jun 2015
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2015-4164, GHSA-jg3g-vx8c-2j78, UBUNTU-CVE-2015-4164

## What is CVE-2015-4164?

CVE-2015-4164 is a medium-severity denial of service vulnerability in Xen Xen, published on 15 Jun 2015. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The compat_iret function in Xen 3.1 through 4.5 iterates the wrong way through a loop, which allows local 32-bit PV guest administrators to cause a denial of service (large loop and system hang) via a hypercall_iret call with EFLAGS.VM set.

Weakness: CWE-399

## Which versions are affected by CVE-2015-4164?

It affects 1 product.


Products: Xen Xen.

## How do I fix CVE-2015-4164?

Apply the vendor's patch.

## Is CVE-2015-4164 being exploited?

There is no known exploitation of CVE-2015-4164 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-2015-4164 and fix it if it is affected.

What it is: CVE-2015-4164 is a medium-severity denial of service vulnerability in Xen Xen, published on 15 Jun 2015. 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-2015-4164 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-2015-4164/ (Markdown: https://insights.sbomify.com/CVE-2015-4164/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2015-4164
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2015-4164
- OSV: https://osv.dev/vulnerability/CVE-2015-4164

---
From sbomify Insights: https://insights.sbomify.com/CVE-2015-4164/
Summaries are generated and may contain mistakes; the official description above is the record.