# CVE-2011-3151: SELinux initscript misuse of touch

> An attacker can exploit a world-writable lockfile creation flaw in the Ubuntu SELinux initscript to allocate zero-byte files on writable filesystems if kernel symlink protections are disabled.

- **Severity:** Medium 5.2 (`CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:L`)
- **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:** No
- **Published:** 22 Apr 2019
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-3wp7-vqr4-g72h

## What is CVE-2011-3151?

CVE-2011-3151 is a medium-severity vulnerability in n/a, published on 22 Apr 2019. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The Ubuntu SELinux initscript before version 1:0.10 used touch to create a lockfile in a world-writable directory. If the OS kernel does not have symlink protections then an attacker can cause a zero byte file to be allocated on any writable filesystem.

Weakness: CWE-693 (Protection Mechanism Failure)

## Which versions are affected by CVE-2011-3151?

It affects 1 product.


Products: Canonical Selinux.

## How do I fix CVE-2011-3151?

No fix has been published for CVE-2011-3151 yet. Limit exposure of the affected software until one is available.

## Is CVE-2011-3151 being exploited?

There is no known exploitation of CVE-2011-3151 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2011-3151 and fix it if it is affected.

What it is: CVE-2011-3151 is a medium-severity vulnerability in n/a, published on 22 Apr 2019. 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-2011-3151 in the wild and no public exploit code.

Affected product: n/a. 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-2011-3151/ (Markdown: https://insights.sbomify.com/CVE-2011-3151/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2011-3151
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2011-3151
- OSV: https://osv.dev/vulnerability/CVE-2011-3151

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From sbomify Insights: https://insights.sbomify.com/CVE-2011-3151/
Summaries are generated and may contain mistakes; the official description above is the record.