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Fencer Intel
high 7.5

GHSA-74fp-r6jw-h4mp json

Kubernetes apimachinery packages vulnerable to unbounded recursion in JSON or YAML parsing

published 4y ago modified 3mo ago also GO-2022-0965

cvss
7.5
version 3.1, GitHub
cisa kev
Not listed
not in CISA's catalog
epss
—
no score, EPSS covers CVEs only
public exploits
0
none known

Summary

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.

```yaml 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

Patch / fix

  • go k8s.io/apimachinery 0.0.0-20190927203648-9ce6eca90e73

Is GHSA-74fp-r6jw-h4mp in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CVSS scores

assigned by version score vector
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
go k8s.io/apimachinery
<0.0.0-20190927203648-9ce6eca90e73
0.0.0-20190927203648-9ce6eca90e73

Classification

Weakness
  • CWE-20 Improper Input Validation
  • CWE-776 Improper Restriction of Recursive Entity References in DTDs

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.