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.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
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.
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 | 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 include 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.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2023-27484 being exploited?
There is no known exploitation of CVE-2023-27484 in the wild and no public exploit code.
Sources
Also known as GHSA-v829-x6hh-cqfq.