# CVE-2012-3494: Denial of service in n/a

> Local guest users can crash the host system by writing to reserved bits in the debug control register on x86-64 Xen hypervisors.

- **Severity:** Low 2.1 (`AV:L/AC:L/Au:N/C:N/I:N/A:P`)
- **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:** 23 Nov 2012
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2012-3494, GHSA-6p48-jg39-2mq7

## What is CVE-2012-3494?

CVE-2012-3494 is a low-severity denial of service vulnerability in Citrix Xenserver, published on 23 Nov 2012. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The set_debugreg hypercall in include/asm-x86/debugreg.h in Xen 4.0, 4.1, and 4.2, and Citrix XenServer 6.0.2 and earlier, when running on x86-64 systems, allows local OS guest users to cause a denial of service (host crash) by writing to the reserved bits of the DR7 debug control register.

Weakness: CWE-264

## Which versions are affected by CVE-2012-3494?

It affects 2 products.


Products: Citrix Xenserver, Xen Xen.

## How do I fix CVE-2012-3494?

Apply the vendor's patch.

## Is CVE-2012-3494 being exploited?

There is no known exploitation of CVE-2012-3494 in the wild and no public exploit code.

## Other vulnerabilities in Citrix Xenserver

- [CVE-2014-4947](https://insights.sbomify.com/CVE-2014-4947/): Memory corruption in n/a (critical 10.0)
- [CVE-2018-14007](https://insights.sbomify.com/CVE-2018-14007/): Path traversal in n/a (critical 9.8)
- [CVE-2015-7705](https://insights.sbomify.com/CVE-2015-7705/): Denial of service in n/a (critical 9.8)
- [CVE-2016-5302](https://insights.sbomify.com/CVE-2016-5302/): Auth bypass in n/a (critical 9.8)
- [CVE-2017-12134](https://insights.sbomify.com/CVE-2017-12134/): Memory corruption in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2012-3494 and fix it if it is affected.

What it is: CVE-2012-3494 is a low-severity denial of service vulnerability in Citrix Xenserver, published on 23 Nov 2012. 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-2012-3494 in the wild and no public exploit code.

Affected product: Citrix Xenserver. 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-2012-3494/ (Markdown: https://insights.sbomify.com/CVE-2012-3494/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2012-3494
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2012-3494
- OSV: https://osv.dev/vulnerability/CVE-2012-3494

---
From sbomify Insights: https://insights.sbomify.com/CVE-2012-3494/
Summaries are generated and may contain mistakes; the official description above is the record.