# CVE-2023-27484: Unchecked fieldpath index in Composition's patches can lead to arbitrary memory allocation in crossplane

> Privileged users can cause excessive memory usage and OOM kills by specifying high indices in Crossplane Compositions, requiring an upgrade to fix.

- **Severity:** Medium 6.2 (`CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Mar 2023
- **Updated:** 25 Feb 2025
- **Also known as:** GHSA-v829-x6hh-cqfq

## What is CVE-2023-27484?

CVE-2023-27484 is a medium-severity denial of service vulnerability in crossplane, published on 9 Mar 2023. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

crossplane-runtime is a set of go libraries used to build Kubernetes controllers in Crossplane and its related stacks. In affected versions an already highly privileged user able to create or update Compositions can specify an arbitrarily high index in a patch's `ToFieldPath`, which could lead to excessive memory usage once such Composition is selected for a Composite resource. Compositions allow users to specify patches inserting elements into arrays at an arbitrary index. When a Composition is selected for a Composite Resource, patches are evaluated and if a specified index is greater than the current size of the target slice, Crossplane will grow that slice up to the specified index, which could lead to an excessive amount of memory usage and therefore the Pod being OOM-Killed. The index is already capped to the maximum value for a uint32 (4294967295) when parsed, but that is still an unnecessarily large value. This issue has been addressed in versions 1.11.2, 1.10.3, and 1.9.2. Users are advised to upgrade. Users unable to upgrade can restrict write privileges on Compositions to only admin users as a workaround.

Weakness: CWE-400 (Uncontrolled Resource Consumption), CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2023-27484?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/crossplane/crossplane` | Go | All versions | 1.9.2 |
| `github.com/crossplane/crossplane` | Go | All versions | 1.9.2 |
| `github.com/crossplane/crossplane` | Go | From 1.10.0 | 1.10.3 |
| `github.com/crossplane/crossplane` | Go | From 1.10.0 | 1.10.3 |
| `github.com/crossplane/crossplane` | Go | From 1.11.0 | 1.11.2 |
| `github.com/crossplane/crossplane` | Go | From 1.11.0 | 1.11.2 |

Products: Crossplane Crossplane.

## How do I fix CVE-2023-27484?

Upgrade github.com/crossplane/crossplane to a fixed version for your release line: 1.9.2, 1.10.3 or 1.11.2.

## Is CVE-2023-27484 being exploited?

There is no known exploitation of CVE-2023-27484 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-27484 and fix it if it is affected.

What it is: CVE-2023-27484 is a medium-severity denial of service vulnerability in crossplane, published on 9 Mar 2023. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-27484 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/crossplane/crossplane (Go): affected all versions; fixed in 1.9.2
- github.com/crossplane/crossplane (Go): affected all versions; fixed in 1.9.2
- github.com/crossplane/crossplane (Go): affected from 1.10.0; fixed in 1.10.3
- github.com/crossplane/crossplane (Go): affected from 1.10.0; fixed in 1.10.3
- github.com/crossplane/crossplane (Go): affected from 1.11.0; fixed in 1.11.2
- github.com/crossplane/crossplane (Go): affected from 1.11.0; fixed in 1.11.2

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-2023-27484/ (Markdown: https://insights.sbomify.com/CVE-2023-27484/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-27484
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-27484
- OSV: https://osv.dev/vulnerability/CVE-2023-27484

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-27484/
Summaries are generated and may contain mistakes; the official description above is the record.