# CVE-2012-0055: Missing authorization in OverlayFS

> Attackers can bypass security restrictions in OverlayFS due to missing inode checks, potentially leading to unauthorized actions and privilege escalation.

- **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:** No
- **Published:** 19 Feb 2020
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-9h57-rmgj-c639

## What is CVE-2012-0055?

CVE-2012-0055 is a high-severity missing authorization vulnerability in Canonical Ubuntu Linux, published on 19 Feb 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

OverlayFS in the Linux kernel before 3.0.0-16.28, as used in Ubuntu 10.0.4 LTS and 11.10, is missing inode security checks which could allow attackers to bypass security restrictions and perform unauthorized actions.

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2012-0055?

It affects 2 products.


Products: Canonical Ubuntu Linux, Linux kernel.

## How do I fix CVE-2012-0055?

No fix has been published for CVE-2012-0055 yet. Limit exposure of the affected software until one is available.

## Is CVE-2012-0055 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2012-0055 exists.

Public exploit code:

- OverlayFS inode Security Checks - 'inode.c' Local Security Bypass (exploitdb)

## Other vulnerabilities in Canonical Ubuntu Linux

- [CVE-2020-11651](https://insights.sbomify.com/CVE-2020-11651/): SaltStack Salt Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2020-7247](https://insights.sbomify.com/CVE-2020-7247/): OpenSMTPD Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2019-16928](https://insights.sbomify.com/CVE-2019-16928/): Exim Out-of-bounds Write (critical 9.8, exploited in the wild)
- [CVE-2018-6789](https://insights.sbomify.com/CVE-2018-6789/): Exim Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2015-2590](https://insights.sbomify.com/CVE-2015-2590/): Oracle Java SE and Java SE Embedded Remote Code Execution (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2012-0055 and fix it if it is affected.

What it is: CVE-2012-0055 is a high-severity missing authorization vulnerability in Canonical Ubuntu Linux, published on 19 Feb 2020. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2012-0055 exists.

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-2012-0055/ (Markdown: https://insights.sbomify.com/CVE-2012-0055/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2012-0055
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2012-0055
- OSV: https://osv.dev/vulnerability/CVE-2012-0055

---
From sbomify Insights: https://insights.sbomify.com/CVE-2012-0055/
Summaries are generated and may contain mistakes; the official description above is the record.