CVE-2023-27484 — crossplane
MEDIUMCVE-2023-27484 is a medium-severity (CVSS 6.2) Improper Input Validation vulnerability in github.com/crossplane/crossplane. A fix is available for github.com/crossplane/crossplane — see the affected versions and patch details below.
Unchecked fieldpath index in Composition's patches can lead to arbitrary memory allocation in crossplane
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-27484.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
github.com/crossplane/crossplane🐹github.com/crossplane/crossplane🐹github.com/crossplane/crossplaneReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/crossplane/crossplane | all versions | 1.9.2go get github.com/crossplane/crossplane@v1.9.2 |
| 🐹Go | github.com/crossplane/crossplane | ≥ 1.10.0&&< 1.10.3 | 1.10.3go get github.com/crossplane/crossplane@v1.10.3 |
| 🐹Go | github.com/crossplane/crossplane | ≥ 1.11.0&&< 1.11.2 | 1.11.2go get github.com/crossplane/crossplane@v1.11.2 |
Affected Products
crossplanecrossplaneDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/crossplane/crossplane, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/crossplane/crossplane to 1.9.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-27484 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
Frequently Asked Questions
Is CVE-2023-27484 in your dependencies?
Find it across Go, including transitive dependencies.