Vulnerability GHSA-xfqj-r5qw-8g4j

High Risk
HIGH RISK
CVSS Score: 8.3
Score Range: 7.0–8.9
High severity vulnerabilities (CVSS 7.0–8.9). Serious vulnerabilities that should be prioritized soon after critical fixes.
6 months ago
April 16, 2026 at 10:47 PM UTC
Paperclip: Unauthenticated Access to Multiple API Endpoints in Authenticated Mode
0.2.2 - 2026.416.0-canary.1
0.2.2 - 2026.416.0-canary.1

Summary

Paperclip: Unauthenticated Access to Multiple API Endpoints in Authenticated Mode

Details

Summary

Several API endpoints in authenticated mode have no authentication at all. They respond to completely unauthenticated requests with sensitive data or allow state-changing operations. No account, no session, no API key needed.

Verified against the latest version.

Discord: sagi03581

Steps to Reproduce

1. Unauthenticated issue data access

GET /api/heartbeat-runs/:runId/issues returns issue data for a heartbeat run with zero authentication. Every other endpoint in server/src/routes/activity.ts calls assertCompanyAccess, but this one was missed.

curl -s http://<target>:3100/api/heartbeat-runs/00000000-0000-0000-0000-000000000001/issues
# -> []  (HTTP 200, not 401 or 403)

If an attacker obtains a valid run UUID (from logs, error messages, shared URLs, or by probing), they can read issue data without any credentials.

2. Unauthenticated CLI auth challenge creation

POST /api/cli-auth/challenges creates a CLI authentication challenge with no actor check at all. The handler at server/src/routes/access.ts:1638-1659 skips any auth verification.

curl -s -X POST -H "Content-Type: application/json" \
  -d '{"command":"test"}' \
  http://<target>:3100/api/cli-auth/challenges
# returns challenge ID, token, and a pre-generated board API key

The response includes a boardApiToken that becomes active once the challenge is approved. Combined with open registration (separate report), this enables persistent API key generation.

3. Unauthenticated agent instruction / system prompt leakage

These endpoints in server/src/routes/access.ts require no authentication:

curl -s http://<target>:3100/api/skills/index
# returns all available skill endpoints

curl -s http://<target>:3100/api/skills/paperclip
# returns the FULL agent heartbeat procedure including:
#   - every API endpoint and its parameters
#   - authentication mechanism (env var names, header formats)
#   - the complete agent coordination protocol
#   - the agent creation/hiring workflow

curl -s http://<target>:3100/api/skills/paperclip-create-agent
# returns the full agent creation workflow with adapter configs

This hands an attacker a complete map of the internal API without authenticating. It also leaks how agents authenticate, how heartbeats work, and what adapter configurations are available.

4. Unauthenticated deployment configuration disclosure

GET /api/health returns deployment mode, exposure setting, auth status, bootstrap status, version, and feature flags.

curl -s http://<target>:3100/api/health
# {
#   "deploymentMode": "authenticated",
#   "deploymentExposure": "public",
#   "authReady": true,
#   "bootstrapStatus": "ready",
#   "version": "2026.403.0",
#   ...
# }

Tells an attacker exactly how the instance is configured, whether registration is available, and what version is running.

Impact

  • Data exposure: heartbeat run issues accessible without credentials. Agent instructions and full API structure exposed to anyone.
  • Reconnaissance: an attacker can fingerprint the deployment (mode, version, features) and map the entire internal API before attempting anything else.
  • Auth bypass stepping stone: unauthenticated CLI challenge creation is a building block for the full RCE chain (reported separately).

Suggested Fixes

  1. Add authentication to heartbeat run issues in server/src/routes/activity.ts:

    • GET /api/heartbeat-runs/:runId/issues -- add assertCompanyAccess like every other endpoint in the same file
  2. Add authentication to CLI challenge creation in server/src/routes/access.ts:

    • POST /api/cli-auth/challenges -- add assertBoard at minimum
  3. Add authentication to skill endpoints in server/src/routes/access.ts:

    • GET /api/skills/available
    • GET /api/skills/index
    • GET /api/skills/:skillName
  4. Reduce health endpoint information -- consider removing deploymentMode, deploymentExposure, and version from the unauthenticated response, or gating the full response behind assertBoard

  5. Consider a global auth rejection middleware for all /api/* routes in authenticated mode. Currently unauthenticated requests get actor: { type: "none" } and pass through to next(), relying on each route handler to check individually. A missing check means an open endpoint. Rejecting type: "none" at the middleware level for all routes except an explicit public allowlist (health, sign-in, sign-up, webhooks) would prevent this class of bug entirely.

Contact

Discord: sagi03581

Happy to help verify fixes or provide additional details.

Impacted packages

Timeline

Published
6 months ago
April 16, 2026 at 10:47 PM UTC
Fixed (2026.416.0)
6 months ago
April 23, 2026 at 02:21 PM UTC
Last Modified
6 months ago
April 16, 2026 at 11:06 PM UTC