# CVE-2016-1576: Privilege escalation in n/a

> Local attackers can gain privileges by exploiting overlayfs mount namespace restrictions to execute crafted setuid programs.

- **Severity:** High 7.8 (`CVSS:3.1/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:** Yes
- **Published:** 2 May 2016
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2016-1576, GHSA-6774-jh98-f2hq, UBUNTU-CVE-2016-1576

## What is CVE-2016-1576?

CVE-2016-1576 is a high-severity vulnerability in Canonical Ubuntu Linux, published on 2 May 2016. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The overlayfs implementation in the Linux kernel through 4.5.2 does not properly restrict the mount namespace, which allows local users to gain privileges by mounting an overlayfs filesystem on top of a FUSE filesystem, and then executing a crafted setuid program.

## Which versions are affected by CVE-2016-1576?

It affects 4 products.


Products: Canonical Ubuntu Core, Canonical Ubuntu Linux, Canonical Ubuntu Touch, Linux kernel.

## How do I fix CVE-2016-1576?

Apply the vendor's patch.

## Is CVE-2016-1576 being exploited?

There is no known exploitation of CVE-2016-1576 in the wild and no public exploit code.

Public exploit code:

- Ubuntu 15.10 - 'USERNS ' Overlayfs Over Fuse Privilege Escalation (exploitdb)

## Other vulnerabilities in Canonical Ubuntu Linux

- [CVE-2016-1575](https://insights.sbomify.com/CVE-2016-1575/): Privilege escalation in n/a (high 7.8)
- [CVE-2015-8325](https://insights.sbomify.com/CVE-2015-8325/): Privilege escalation in n/a (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-1576 and fix it if it is affected.

What it is: CVE-2016-1576 is a high-severity vulnerability in Canonical Ubuntu Linux, published on 2 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-2016-1576 in the wild and no public exploit code.

Affected product: Canonical Ubuntu Linux. 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-2016-1576/ (Markdown: https://insights.sbomify.com/CVE-2016-1576/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-1576
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-1576
- OSV: https://osv.dev/vulnerability/CVE-2016-1576

---
From sbomify Insights: https://insights.sbomify.com/CVE-2016-1576/
Summaries are generated and may contain mistakes; the official description above is the record.