# CVE-2020-8569: Kubernetes CSI snapshot-controller DoS

> Attackers can cause a crashloop in the Kubernetes CSI snapshot-controller by submitting specific VolumeSnapshot resources, preventing volume snapshot operations.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 21 Jan 2021
- **Updated:** 17 Sep 2024
- **Also known as:** GHSA-hwrr-rhmm-vcvf

## What is CVE-2020-8569?

CVE-2020-8569 is a medium-severity vulnerability in Kubernetes CSI Snapshotter, published on 21 Jan 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Kubernetes CSI snapshot-controller prior to v2.1.3 and v3.0.2 could panic when processing a VolumeSnapshot custom resource when: - The VolumeSnapshot referenced a non-existing PersistentVolumeClaim and the VolumeSnapshot did not reference any VolumeSnapshotClass. - The snapshot-controller crashes, is automatically restarted by Kubernetes, and processes the same VolumeSnapshot custom resource after the restart, entering an endless crashloop. Only the volume snapshot feature is affected by this vulnerability. When exploited, users can’t take snapshots of their volumes or delete the snapshots. All other Kubernetes functionality is not affected.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2020-8569?

4 open source packages ship an affected version, including github.com/kubernetes-csi/external-snapshotter/v2 and github.com/kubernetes-csi/external-snapshotter/v3. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/kubernetes-csi/external-snapshotter/v2` | Go | From 2.0.0 | 2.1.3 |
| `github.com/kubernetes-csi/external-snapshotter/v2` | Go | From 2.0.0 | 2.1.3 |
| `github.com/kubernetes-csi/external-snapshotter/v3` | Go | From 3.0.0 | 3.0.2 |
| `github.com/kubernetes-csi/external-snapshotter/v3` | Go | From 3.0.0 | 3.0.2 |

Products: Kubernetes Container Storage Interface Snapshotter.

## How do I fix CVE-2020-8569?

Upgrade github.com/kubernetes-csi/external-snapshotter/v2 to 2.1.3 or later.

## Is CVE-2020-8569 being exploited?

There is no known exploitation of CVE-2020-8569 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-8569 and fix it if it is affected.

What it is: CVE-2020-8569 is a medium-severity vulnerability in Kubernetes CSI Snapshotter, published on 21 Jan 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-8569 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/kubernetes-csi/external-snapshotter/v2 (Go): affected from 2.0.0; fixed in 2.1.3
- github.com/kubernetes-csi/external-snapshotter/v2 (Go): affected from 2.0.0; fixed in 2.1.3
- github.com/kubernetes-csi/external-snapshotter/v3 (Go): affected from 3.0.0; fixed in 3.0.2
- github.com/kubernetes-csi/external-snapshotter/v3 (Go): affected from 3.0.0; fixed in 3.0.2

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-2020-8569/ (Markdown: https://insights.sbomify.com/CVE-2020-8569/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-8569
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-8569
- OSV: https://osv.dev/vulnerability/CVE-2020-8569

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-8569/
Summaries are generated and may contain mistakes; the official description above is the record.