# CVE-2016-4480: Privilege escalation in n/a

> Local guest OS users can gain privileges by exploiting improper handling of page table entry bits in the Xen hypervisor.

- **Severity:** High 8.4 (`CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 May 2016
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2016-4480, GHSA-mrv5-xm7c-h532, UBUNTU-CVE-2016-4480

## What is CVE-2016-4480?

CVE-2016-4480 is a high-severity vulnerability in Xen Xen, published on 18 May 2016. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The guest_walk_tables function in arch/x86/mm/guest_walk.c in Xen 4.6.x and earlier does not properly handle the Page Size (PS) page table entry bit at the L4 and L3 page table levels, which might allow local guest OS users to gain privileges via a crafted mapping of memory.

Weakness: CWE-264

## Which versions are affected by CVE-2016-4480?

It affects 2 products.


Products: Oracle Vm Server, Xen Xen.

## How do I fix CVE-2016-4480?

Apply the vendor's patch.

## Is CVE-2016-4480 being exploited?

There is no known exploitation of CVE-2016-4480 in the wild and no public exploit code.

## Other vulnerabilities in Xen Xen

- [CVE-2016-4962](https://insights.sbomify.com/CVE-2016-4962/): Privilege escalation in n/a (medium 6.7)
- [CVE-2017-3242](https://insights.sbomify.com/CVE-2017-3242/): Denial of service in LDOMS (medium 5.9)
- [CVE-2015-0452](https://insights.sbomify.com/CVE-2015-0452/): Information disclosure in n/a (medium 4.3)
- [CVE-2020-2571](https://insights.sbomify.com/CVE-2020-2571/): Missing authorization in LDOMS (low 3.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-4480 and fix it if it is affected.

What it is: CVE-2016-4480 is a high-severity vulnerability in Xen Xen, published on 18 May 2016. 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-2016-4480 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-2016-4480/ (Markdown: https://insights.sbomify.com/CVE-2016-4480/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-4480
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-4480
- OSV: https://osv.dev/vulnerability/CVE-2016-4480

---
From sbomify Insights: https://insights.sbomify.com/CVE-2016-4480/
Summaries are generated and may contain mistakes; the official description above is the record.