n8n is an open source workflow automation platform. From version 1.65.0 to before 1.114.3, the use of Buffer.allocUnsafe() and Buffer.allocUnsafeSlow() in the task runner allowed untrusted code to allocate uninitialized memory. Such uninitialized buffers could contain residual data from within the same Node.js process (for example, data from prior requests, tasks, secrets, or tokens), resulting in potential information disclosure. This issue has been patched in version 1.114.3.

Affected: npm: n8n

### Impact

The use of `Buffer.allocUnsafe()` and `Buffer.allocUnsafeSlow()` in the task runner allowed untrusted code to allocate uninitialized memory. Such uninitialized buffers could contain residual data from within the same Node.js process (for example, data from prior requests, tasks, secrets, or tokens), resulting in potential information disclosure.

Only authenticated users are able to execute code through Task Runners.

This issue affected any deployment in which both of the following conditions were met: - Task Runners were enabled using `N8N_RUNNERS_ENABLED=true` (default: false) - Code Node was enabled (default: true)

### Patches

Access to unsafe Buffer functions has been removed from the task runner sandbox. All buffer allocations are now zero-filled by default.

- **Fixed in:** 1.114.3 & 1.115.0 - **Action:** It is strongly recommended to upgrade to version ≥ 1.114.3 as soon as possible.

Changes introduced in this patch include: - Routing all buffer allocations through `Buffer.alloc` (which zero-fills) operations where applicable - Adding regression tests to ensure continued enforcement of safe allocation practices

### Workarounds

If an immediate upgrade cannot be applied, the following hardening steps are recommended:

- Disable the Code Node by adding `n8n-nodes-base.code` to the `NODES_EXCLUDE` environment variable - Prefer external mode for isolation: run Task Runners in external mode so that untrusted task code executes in a separate sidecar…

Ein entfernter, authentisierter oder anonymer Angreifer kann mehrere Schwachstellen in n8n ausnutzen, um beliebigen Code auszuführen, sich erhöhte Berechtigungen zu verschaffen, Cross-Site-Scripting-Angriffe durchzuführen und vertrauliche Informationen offenzulegen. Über einige dieser Schwachstellen sind weitere Angriffe möglich, wie beispielsweise die Übernahme von Konten, das Hijacking von Sitzungen und die vollständige Kompromittierung des Systems.