Vulnerability in Kubernetes
CVE-2021-25740
A security issue was discovered with Kubernetes that could enable users to send network traffic to locations they would otherwise not have access to via a confused deputy attack.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.1 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.020 (79.5th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 79th percentile — 79.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.020 · newest: 0.020 · change: 0.000
Affected products
- Kubernetes — versions next of 1.22.2, next of 1.21.5, next of 1.20.11
Weakness classification (CWE)
Public proof-of-concept exploits
- ARPSyndicate/cvemon
- adavarski/HomeLab-Proxmox-k8s-DevSecOps-playground
- adavarski/HomeLab-k8s-DevSecOps-playground
- atwilsecurity/k8s-Security
- dli408097/k8s-security
- hacking-kubernetes/hacking-kubernetes.info
- kajogo777/kubernetes-misconfigured
- magnologan/awesome-k8s-security
- rosyrut/K8S-Security
- sunilbennur/kubernetes-Security-master
References
- groups.google.com/g/kubernetes-security-announce/c/WYE9ptrhSLE (Mailing List, Third Party Advisory, Mitigation)
- github.com/kubernetes/kubernetes/issues/103675 (Third Party Advisory, Mitigation)
- security.netapp.com/advisory/ntap-20211014-0001/ (Third Party Advisory)
- kubernetes.io/blog/2026/05/26/reconciling-unfixed-kubernetes-cves/
Frequently asked questions
- What is CVE-2021-25740?
- CVE-2021-25740 is a low-severity vulnerability in Kubernetes, classified under Unintended Proxy or Intermediary (Confused Deputy). CVSS score: 3.1/10. Published 2021-09-20.
- How severe is CVE-2021-25740?
- Low severity. CVSS v3 base score is 3.1 out of 10.
- Is CVE-2021-25740 known to be exploited?
- 10 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.