# CVE-2015-6855: Denial of service in n/a

> A guest user can crash the QEMU instance by sending specific IDE commands to an ATAPI device, causing a divide-by-zero error.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 6 Nov 2015
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2015-6855, GHSA-8gcq-wcj5-xgq6, UBUNTU-CVE-2015-6855

## What is CVE-2015-6855?

CVE-2015-6855 is a high-severity denial of service vulnerability in Canonical Ubuntu Linux, published on 6 Nov 2015. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

hw/ide/core.c in QEMU does not properly restrict the commands accepted by an ATAPI device, which allows guest users to cause a denial of service or possibly have unspecified other impact via certain IDE commands, as demonstrated by a WIN_READ_NATIVE_MAX command to an empty drive, which triggers a divide-by-zero error and instance crash.

Weakness: CWE-369 (Divide By Zero)

## Which versions are affected by CVE-2015-6855?

It affects 7 products.


Products: Arista Eos, Canonical Ubuntu Linux, Debian Debian Linux, Fedoraproject Fedora, Qemu Qemu, Suse Linux Enterprise Desktop, Suse Linux Enterprise Server.

## How do I fix CVE-2015-6855?

Apply the vendor's patch.

## Is CVE-2015-6855 being exploited?

There is no known exploitation of CVE-2015-6855 in the wild and no public exploit code.

## Other vulnerabilities in Canonical Ubuntu Linux

- [CVE-2026-7473](https://insights.sbomify.com/CVE-2026-7473/): Arista Extensible Operating System Incomplete Comparison with Missing Factors (medium 6.9, exploited in the wild)
- [CVE-2015-8236](https://insights.sbomify.com/CVE-2015-8236/): Privilege escalation in n/a (critical 10.0)
- [CVE-2020-10188](https://insights.sbomify.com/CVE-2020-10188/): Memory corruption in n/a (critical 9.8)
- [CVE-2017-18017](https://insights.sbomify.com/CVE-2017-18017/): Use after free in n/a (critical 9.8)
- [CVE-2017-14491](https://insights.sbomify.com/CVE-2017-14491/): Memory corruption in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2015-6855 and fix it if it is affected.

What it is: CVE-2015-6855 is a high-severity denial of service vulnerability in Canonical Ubuntu Linux, published on 6 Nov 2015. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2015-6855 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-2015-6855/ (Markdown: https://insights.sbomify.com/CVE-2015-6855/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2015-6855
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2015-6855
- OSV: https://osv.dev/vulnerability/CVE-2015-6855

---
From sbomify Insights: https://insights.sbomify.com/CVE-2015-6855/
Summaries are generated and may contain mistakes; the official description above is the record.