# CVE-2009-1242: Denial of service in n/a

> Guest OS users can cause a denial of service in the Linux kernel KVM subsystem by setting a specific register bit on i386 platforms.

- **Severity:** Medium 4.9 (`AV:L/AC:L/Au:N/C:N/I:N/A:C`)
- **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:** 6 Apr 2009
- **Updated:** 7 Aug 2024
- **Also known as:** GHSA-wqvc-c395-66j7

## What is CVE-2009-1242?

CVE-2009-1242 is a medium-severity denial of service vulnerability in Canonical Ubuntu Linux, published on 6 Apr 2009. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The vmx_set_msr function in arch/x86/kvm/vmx.c in the VMX implementation in the KVM subsystem in the Linux kernel before 2.6.29.1 on the i386 platform allows guest OS users to cause a denial of service (OOPS) by setting the EFER_LME (aka "Long mode enable") bit in the Extended Feature Enable Register (EFER) model-specific register, which is specific to the x86_64 platform.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2009-1242?

It affects 5 products.


Products: Canonical Ubuntu Linux, Debian Debian Linux, Fedoraproject Fedora, Linux kernel, Opensuse Opensuse.

## How do I fix CVE-2009-1242?

Upgrade to a fixed version.

## Is CVE-2009-1242 being exploited?

There is no known exploitation of CVE-2009-1242 in the wild and no public exploit code.

## 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-2009-1242 and fix it if it is affected.

What it is: CVE-2009-1242 is a medium-severity denial of service vulnerability in Canonical Ubuntu Linux, published on 6 Apr 2009. 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-2009-1242 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-2009-1242/ (Markdown: https://insights.sbomify.com/CVE-2009-1242/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2009-1242
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2009-1242
- OSV: https://osv.dev/vulnerability/CVE-2009-1242

---
From sbomify Insights: https://insights.sbomify.com/CVE-2009-1242/
Summaries are generated and may contain mistakes; the official description above is the record.