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GHSA-M983-7426-5HRJ

Vulnerability from github – Published: 2026-03-24 22:25 – Updated: 2026-03-30 20:27
VLAI
Summary
Ech0 authenticated user-list exposed data via public `/api/allusers` endpoint
Details

Summary

A public access-control flaw allows unauthenticated users to retrieve the full user list from GET /api/allusers. This exposes user profile metadata to anyone who can reach the application and enables remote user enumeration.

Details

The vulnerable route is registered as a public endpoint:

  • internal/router/user.go:17
  • appRouterGroup.PublicRouterGroup.GET("/allusers", h.UserHandler.GetAllUsers())

However, the handler appears to have been intended as an authenticated endpoint:

  • internal/handler/user/user.go:177-185
  • API annotations indicate an authentication requirement via @Security ApiKeyAuth

This creates a mismatch between the documented security model and the actual routing configuration. As a result, requests to GET /api/allusers succeed without authentication and return user records, including profile metadata such as usernames, email addresses, role-related flags, avatar values, and locale information.

A negative control against another endpoint that correctly requires authentication further supports that this exposure is unintended: GET /api/user returns 401 Unauthorized when no token is supplied, while GET /api/allusers remains publicly accessible.

Impact

  • Type: Access control bypass / unauthenticated data exposure
  • Who is impacted: Any deployment exposing the API to untrusted networks, and all users whose profile metadata is returned by the endpoint
  • Security impact: Enables remote user enumeration and disclosure of user profile metadata, which may facilitate account reconnaissance, phishing, and targeted credential attacks
  • Attack preconditions: None beyond network access to the affected API endpoint
Severity
5.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Show details on source website
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{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/lin-snow/ech0"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.4.8-0.20260322121226-acbf1fd71011"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-33638"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-862"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-24T22:25:03Z",
    "nvd_published_at": "2026-03-26T21:17:07Z",
    "severity": "MODERATE"
  },
  "details": "### Summary\nA public access-control flaw allows unauthenticated users to retrieve the full user list from `GET /api/allusers`. This exposes user profile metadata to anyone who can reach the application and enables remote user enumeration.\n\n### Details\nThe vulnerable route is registered as a public endpoint:\n\n- `internal/router/user.go:17`\n  - `appRouterGroup.PublicRouterGroup.GET(\"/allusers\", h.UserHandler.GetAllUsers())`\n\nHowever, the handler appears to have been intended as an authenticated endpoint:\n\n- `internal/handler/user/user.go:177-185`\n  - API annotations indicate an authentication requirement via `@Security ApiKeyAuth`\n\nThis creates a mismatch between the documented security model and the actual routing configuration. As a result, requests to `GET /api/allusers` succeed without authentication and return user records, including profile metadata such as usernames, email addresses, role-related flags, avatar values, and locale information.\n\nA negative control against another endpoint that correctly requires authentication further supports that this exposure is unintended: `GET /api/user` returns `401 Unauthorized` when no token is supplied, while `GET /api/allusers` remains publicly accessible.\n\n### Impact\n- **Type:** Access control bypass / unauthenticated data exposure\n- **Who is impacted:** Any deployment exposing the API to untrusted networks, and all users whose profile metadata is returned by the endpoint\n- **Security impact:** Enables remote user enumeration and disclosure of user profile metadata, which may facilitate account reconnaissance, phishing, and targeted credential attacks\n- **Attack preconditions:** None beyond network access to the affected API endpoint",
  "id": "GHSA-m983-7426-5hrj",
  "modified": "2026-03-30T20:27:17Z",
  "published": "2026-03-24T22:25:03Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/lin-snow/Ech0/security/advisories/GHSA-m983-7426-5hrj"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33638"
    },
    {
      "type": "WEB",
      "url": "https://github.com/lin-snow/Ech0/commit/acbf1fd71011e6b9e1e6a911128056a19862f681"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/lin-snow/Ech0"
    },
    {
      "type": "WEB",
      "url": "https://github.com/lin-snow/Ech0/releases/tag/v4.2.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Ech0  authenticated user-list exposed data via public `/api/allusers` endpoint  "
}



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