{"answers":{"affected":"3 open source packages ship an affected version, including k8s.io/kubernetes. It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-25736 in the wild and no public exploit code.","fix":"Upgrade k8s.io/kubernetes to 1.21.0 or later.","what":"CVE-2021-25736 is a medium-severity server-side request forgery vulnerability in Kubernetes Kubernetes, published on 30 Oct 2023. An attacker needs administrator access to exploit it, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2021-25736 and fix it if it is affected.\n\nWhat it is: CVE-2021-25736 is a medium-severity server-side request forgery vulnerability in Kubernetes Kubernetes, published on 30 Oct 2023. An attacker needs administrator access to exploit it, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2021-25736 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- k8s.io/kubernetes (Go): affected all versions; fixed in 1.21.0\n- k8s.io/kubernetes (Go): affected all versions; fixed in 1.21.0\n- k8s.io/kubernetes (Go): affected all versions; fixed in 1.21.0\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2021-25736/ (Markdown: https://insights.sbomify.com/CVE-2021-25736/index.md)","id":"CVE-2021-25736","markdown":"https://insights.sbomify.com/CVE-2021-25736/index.md","name":"CVE-2021-25736","record":{"aliases":["GHSA-35c7-w35f-xwgh","GO-2023-2159"],"analysis":{"component_type":"container_or_infrastructure","fix_type":"configuration_change","impacts":["data_read","security_bypass"],"network_reachable":"yes","non_default_config":true,"product_category":"Kubernetes kube-proxy","requires_auth":"high_privilege","summary":"Windows kube-proxy may forward LoadBalancer traffic to local processes if the controller omits the ingress IP, allowing local access to internal services.","user_interaction":"not_required","vuln_class":"ssrf"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"kubernetes","cpe":[{"product":"kubernetes","vendor":"kubernetes"}],"cvss":{"score":5.8,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:N/A:N","version":"3.1"},"cwes":[{"id":"CWE-114","name":"Process Control"}],"description":"Kube-proxy\n on Windows can unintentionally forward traffic to local processes \nlistening on the same port (“spec.ports[*].port”) as a LoadBalancer \nService when the LoadBalancer controller\n does not set the “status.loadBalancer.ingress[].ip” field. Clusters \nwhere the LoadBalancer controller sets the \n“status.loadBalancer.ingress[].ip” field are unaffected.","ecosystems":["Go"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"Windows kube-proxy LoadBalancer contention","id":"CVE-2021-25736","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Go","product":"kubernetes:kubernetes","products":["kubernetes:kubernetes"],"type":"ssrf","year":"2021"},"n_packages":3,"n_references":3,"next":{"headline":"Holes in EndpointSlice Validation Enable Host Network Hijack","id":"CVE-2021-25737"},"packages":[{"ecosystem":"Go","fixed":["1.21.0"],"introduced":["0"],"last_affected":[],"package":"k8s.io/kubernetes","purl":null,"source":"GHSA-35c7-w35f-xwgh"},{"ecosystem":"Go","fixed":["1.21.0"],"introduced":["0"],"last_affected":[],"package":"k8s.io/kubernetes","purl":"pkg:golang/k8s.io/kubernetes","source":"GHSA-35c7-w35f-xwgh"},{"ecosystem":"Go","fixed":["1.21.0"],"introduced":["0"],"last_affected":[],"package":"k8s.io/kubernetes","purl":"pkg:golang/k8s.io/kubernetes","source":"GO-2023-2159"}],"prev":{"headline":"Validating Admission Webhook does not observe some previous fields","id":"CVE-2021-25735"},"products":["Kubernetes"],"published":"2023-10-30","related":[{"cvss_score":9.8,"headline":"Privilege Escalation in Kubernetes","id":"CVE-2018-1002105","kev_date_added":null,"published":"2018-12-05"},{"cvss_score":9.8,"headline":"Kubernetes Privilege Escalation","id":"CVE-2017-1000056","kev_date_added":null,"published":"2017-07-13"},{"cvss_score":9.8,"headline":"Authorization bypass in Openshift","id":"CVE-2016-1906","kev_date_added":null,"published":"2016-02-03"},{"cvss_score":8.8,"headline":"Kubernetes - Windows nodes - Insufficient input sanitization leads to privilege escalation","id":"CVE-2023-3676","kev_date_added":null,"published":"2023-10-31"},{"cvss_score":8.8,"headline":"Kubernetes - Windows nodes - Insufficient input sanitization leads to privilege escalation","id":"CVE-2023-3955","kev_date_added":null,"published":"2023-10-31"},{"cvss_score":8.8,"headline":"Symlink Exchange Can Allow Host Filesystem Access","id":"CVE-2021-25741","kev_date_added":null,"published":"2021-09-20"},{"cvss_score":8.8,"headline":"Path traversal in Kubernetes","id":"CVE-2017-1002101","kev_date_added":null,"published":"2018-03-13"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"CC BY 4.0","name":"Go Vulnerability Database","prefix":"GO"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2025-06-12","vendors":["Kubernetes"]},"summary":"Windows kube-proxy may forward LoadBalancer traffic to local processes if the controller omits the ingress IP, allowing local access to internal services.","url":"https://insights.sbomify.com/CVE-2021-25736/"}