# CVE-2017-10917: Null dereference in n/a

> Guest OS users can crash the host or read sensitive data via a NULL pointer dereference in Xen's event channel port validation.

- **Severity:** Critical 9.1 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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:** 5 Jul 2017
- **Updated:** 5 Aug 2024
- **Also known as:** ALPINE-CVE-2017-10917, DEBIAN-CVE-2017-10917, GHSA-v32f-p355-m49p, UBUNTU-CVE-2017-10917

## What is CVE-2017-10917?

CVE-2017-10917 is a critical vulnerability in Xen Xen, published on 5 Jul 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Xen through 4.8.x does not validate the port numbers of polled event channel ports, which allows guest OS users to cause a denial of service (NULL pointer dereference and host OS crash) or possibly obtain sensitive information, aka XSA-221.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2017-10917?

It affects 1 product.


Products: Xen Xen.

## How do I fix CVE-2017-10917?

Apply the vendor's patch.

## Is CVE-2017-10917 being exploited?

There is no known exploitation of CVE-2017-10917 in the wild and no public exploit code.

## Other vulnerabilities in Xen Xen

- [CVE-2017-10912](https://insights.sbomify.com/CVE-2017-10912/): Privilege escalation in n/a (critical 10.0)
- [CVE-2017-10918](https://insights.sbomify.com/CVE-2017-10918/): Memory corruption in n/a (critical 10.0)
- [CVE-2017-10920](https://insights.sbomify.com/CVE-2017-10920/): Memory corruption in n/a (critical 10.0)
- [CVE-2017-10921](https://insights.sbomify.com/CVE-2017-10921/): Memory corruption in n/a (critical 10.0)
- [CVE-2025-27466](https://insights.sbomify.com/CVE-2025-27466/): Mutiple vulnerabilities in the Viridian interface (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-10917 and fix it if it is affected.

What it is: CVE-2017-10917 is a critical vulnerability in Xen Xen, published on 5 Jul 2017. 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-2017-10917 in the wild and no public exploit code.

Affected product: Xen Xen. 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-2017-10917/ (Markdown: https://insights.sbomify.com/CVE-2017-10917/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-10917
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-10917
- OSV: https://osv.dev/vulnerability/CVE-2017-10917

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-10917/
Summaries are generated and may contain mistakes; the official description above is the record.