Medium severity · published Sep 20, 2021
CVE-2020-8561
A security issue was discovered in Kubernetes where actors that control the responses of MutatingWebhookConfiguration or ValidatingWebhookConfiguration requests are able to…
4.1
CVSS
2.1%
EPSS
No
On KEV
Description
A security issue was discovered in Kubernetes where actors that control the responses of MutatingWebhookConfiguration or ValidatingWebhookConfiguration requests are able to redirect kube-apiserver requests to private networks of the apiserver. If that user can view kube-apiserver logs when the log level is set to 10, they can view the redirected responses and headers in the logs.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Confidentiality
Low
Integrity
None
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)2.1% · higher than 82% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KU
Kubernetes · Kubernetes
1.20.11; 1.21.5; 1.22.2 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-8561
CVE.org
https://www.cve.org/CVERecord?id=CVE-2020-8561
Mitigation
https://github.com/kubernetes/kubernetes/issues/104720
Mailing List
https://groups.google.com/g/kubernetes-security-announce/c/RV2IhwcrQsY
kubernetes.io
https://kubernetes.io/blog/2026/05/26/reconciling-unfixed-kubernetes-cves/
Third Party Advisory
https://security.netapp.com/advisory/ntap-20211014-0002/
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