{
  "affected": [
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "avo"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.31.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-284",
      "CWE-639"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-04-24T16:11:28Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Summary\n\nA critical Broken Access Control vulnerability was identified in the `ActionsController` of the Avo framework (v3.x). Due to insecure action lookup logic, an authenticated user can execute any Action class (descendants of `Avo::BaseAction`) on any resource, even if the action is not registered for that specific resource. This leads to Privilege Escalation and unauthorized data manipulation across the entire application.\n\n### Details\n\nThe vulnerability exists in the `action_class` method within `app/controllers/avo/actions_controller.rb`.\n\n#### Vulnerable Code\n\n```ruby\ndef action_class\n  # It searches through ALL descendants of BaseAction without resource validation\n  Avo::BaseAction.descendants.find do |action|\n    action.to_s == params[:action_id]\n  end\nend\n```\n\nThe controller identifies the action class to execute solely based on the `params[:action_id]` by searching through all `BaseAction` descendants. It fails to verify whether the requested action is actually permitted or registered for the resource context specified in the request URL (e.g., `/admin/resources/posts/actions`).\n\nConsequently, an attacker can invoke sensitive actions (e.g., `Avo::Actions::ToggleAdmin`) through an unrelated resource endpoint (e.g., `Post`), bypassing the intended resource-action mapping.\n\n### Impact\n\nThis flaw results in significant security risks:\n\n- **Privilege Escalation:** An authenticated user with low privileges can execute administrative actions (like toggling admin roles) to escalate their own or others\u0027 permissions.\n- **Unauthorized Operations:** Actions designed for restricted resources can be triggered against any record ID in the database.\n- **Data Integrity Compromise:** Attackers can perform unauthorized destructive operations (e.g., Delete, Archive, or Update) on records they should not have access to.\n\n### Proof of Concept (PoC)\n\n**Steps to Reproduce:**\n\n01. Log in to the Avo admin panel with limited permissions.\n02. Identify a target record ID (e.g., User ID: 1) and a sensitive action class (e.g., `Avo::Actions::ToggleAdmin`).\n03. Send a POST request to a resource endpoint where the target action is not registered:\n    - **URL:** `POST /admin/resources/posts/actions`\n    - **Payload:** `action_id=Avo::Actions::ToggleAdmin\u0026fields[avo_resource_ids]=1`\n04. The server executes the `ToggleAdmin` logic on User 1, even though the request was made through the `posts` resource context.\n\n**PoC Script Snippet:**\n\n```python\n# Simulating the unauthorized action execution\ndata = {\n    \u0027action_id\u0027: \u0027Avo::Actions::ToggleAdmin\u0027,\n    \u0027fields[avo_resource_ids]\u0027: \u00271\u0027, # Target Record ID\n    \u0027authenticity_token\u0027: csrf_token\n}\nresponse = session.post(f\"{BASE_URL}/admin/resources/posts/actions\", data=data)\n```\n\n### Remediation\n\nRestrict the action lookup to only those actions explicitly registered for the current resource context:\n\n```ruby\ndef action_class\n  # Validate that the action is registered for the current resource\n  @resource.get_actions.find do |action|\n    action.to_s == params[:action_id]\n  end\nend\n```\n\n### Discoverer\n\nIllunight",
  "id": "GHSA-qc5p-3mg5-9fh8",
  "modified": "2026-04-24T16:11:28Z",
  "published": "2026-04-24T16:11:28Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/avo-hq/avo/security/advisories/GHSA-qc5p-3mg5-9fh8"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/avo-hq/avo"
    }
  ],
  "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"
    }
  ],
  "summary": "Avo: Broken Access Control Through Unauthorized Execution of Arbitrary Action Classes Across Resources"
}