# CVE-2017-1000256: Misconfiguration in n/a

> Libvirt fails to validate SSL/TLS certificates by default, allowing attackers to bypass security checks in virtualization environments.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/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:** 31 Oct 2017
- **Updated:** 5 Aug 2024
- **Also known as:** ALPINE-CVE-2017-1000256, DEBIAN-CVE-2017-1000256, DSA-4003-1, GHSA-gq8m-rwgg-6vv3, SUSE-SU-2017:2850-1

## What is CVE-2017-1000256?

CVE-2017-1000256 is a high-severity vulnerability in Debian Debian Linux, published on 31 Oct 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

libvirt version 2.3.0 and later is vulnerable to a bad default configuration of "verify-peer=no" passed to QEMU by libvirt resulting in a failure to validate SSL/TLS certificates by default.

Weakness: CWE-295 (Improper Certificate Validation)

## Which versions are affected by CVE-2017-1000256?

It affects 2 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `libvirt` | SUSE:Linux Enterprise Desktop 12 SP3 | All versions | 3.3.0-5.8.1 |
| `libvirt` | SUSE:Linux Enterprise Server 12 SP3 | All versions | 3.3.0-5.8.1 |
| `libvirt` | SUSE:Linux Enterprise Server for SAP Applications 12 SP3 | All versions | 3.3.0-5.8.1 |
| `libvirt` | SUSE:Linux Enterprise Software Development Kit 12 SP3 | All versions | 3.3.0-5.8.1 |

Products: Debian Debian Linux, Redhat Libvirt.

## How do I fix CVE-2017-1000256?

Apply the vendor's patch.

## Is CVE-2017-1000256 being exploited?

There is no known exploitation of CVE-2017-1000256 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-1000256 and fix it if it is affected.

What it is: CVE-2017-1000256 is a high-severity vulnerability in Debian Debian Linux, published on 31 Oct 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-2017-1000256 in the wild and no public exploit code.

Affected product: Debian Debian 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-2017-1000256/ (Markdown: https://insights.sbomify.com/CVE-2017-1000256/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-1000256
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-1000256
- OSV: https://osv.dev/vulnerability/CVE-2017-1000256

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-1000256/
Summaries are generated and may contain mistakes; the official description above is the record.