# CVE-2021-25318: rancher: API group not properly specified when creating Kubernetes RBAC resources

> Attackers can modify unauthorized Kubernetes resources due to incorrect RBAC permission assignments in Rancher.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** 15 Jul 2021
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-f9xf-jq4j-vqw4, GO-2024-2768

## What is CVE-2021-25318?

CVE-2021-25318 is a high-severity missing authorization vulnerability in Rancher, published on 15 Jul 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A Incorrect Permission Assignment for Critical Resource vulnerability in Rancher allows users in the cluster to modify resources they should not have access to. This issue affects: Rancher versions prior to 2.5.9 ; Rancher versions prior to 2.4.16.

Weakness: CWE-732 (Incorrect Permission Assignment for Critical Resource)

## Which versions are affected by CVE-2021-25318?

5 open source packages ship an affected version, including github.com/rancher/rancher. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/rancher/rancher` | Go | From 2.0.0 | 2.4.16 |
| `github.com/rancher/rancher` | Go | From 2.0.0 | 2.4.16 |
| `github.com/rancher/rancher` | Go | From 2.0.0+incompatible | None |
| `github.com/rancher/rancher` | Go | From 2.5.0 | 2.5.9 |
| `github.com/rancher/rancher` | Go | From 2.5.0 | 2.5.9 |

Products: Rancher Rancher.

## How do I fix CVE-2021-25318?

Upgrade github.com/rancher/rancher to a fixed version for your release line: 2.4.16 or 2.5.9.

## Is CVE-2021-25318 being exploited?

There is no known exploitation of CVE-2021-25318 in the wild and no public exploit code.

## Other vulnerabilities in Rancher

- [CVE-2021-25320](https://insights.sbomify.com/CVE-2021-25320/): Rancher: Cloud credentials can be used through proxy API by users without access (critical 9.9)
- [CVE-2021-36775](https://insights.sbomify.com/CVE-2021-36775/): Deleting PRTBs associated to a group doesn't cause deletion of corresponding RoleBindings (high 8.8)
- [CVE-2021-36776](https://insights.sbomify.com/CVE-2021-36776/): Steve API proxy impersonation (high 8.8)
- [CVE-2021-31999](https://insights.sbomify.com/CVE-2021-31999/): Rancher: Privilege escalation vulnerability via malicious Connection header (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-25318 and fix it if it is affected.

What it is: CVE-2021-25318 is a high-severity missing authorization vulnerability in Rancher, published on 15 Jul 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-2021-25318 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/rancher/rancher (Go): affected from 2.0.0; fixed in 2.4.16
- github.com/rancher/rancher (Go): affected from 2.0.0; fixed in 2.4.16
- github.com/rancher/rancher (Go): affected from 2.0.0+incompatible; no fix listed
- github.com/rancher/rancher (Go): affected from 2.5.0; fixed in 2.5.9
- github.com/rancher/rancher (Go): affected from 2.5.0; fixed in 2.5.9

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-2021-25318/ (Markdown: https://insights.sbomify.com/CVE-2021-25318/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-25318
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-25318
- OSV: https://osv.dev/vulnerability/CVE-2021-25318

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-25318/
Summaries are generated and may contain mistakes; the official description above is the record.