n8n is an open source workflow automation platform. Prior to 1.123.43, 2.22.1, and 2.20.7, the OAuth1 and OAuth2 credential reconnect endpoints authorized access using credential:read rather than credential:update. An authenticated user with read-only access to a shared credential could initiate an OAuth reconnect flow and overwrite the stored token material for that credential with tokens bound to an external account they control. Workflows relying on the affected credential would subsequently execute under the attackers OAuth identity, enabling data exfiltration to attacker-controlled external services and persistent takeover of shared integrations. This vulnerability is fixed in 1.123.43, 2.22.1, and 2.20.7.
Weakness
The system’s authorization functionality does not prevent one user from gaining access to another user’s data or record by modifying the key value identifying the data.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| N8n | N8n | * | 1.123.43 (excluding) |
| N8n | N8n | 2.0.0 (including) | 2.20.7 (excluding) |
| N8n | N8n | 2.21.0 (including) | 2.22.1 (excluding) |
Extended Description
Retrieval of a user record occurs in the system based on some key value that is under user control. The key would typically identify a user-related record stored in the system and would be used to lookup that record for presentation to the user. It is likely that an attacker would have to be an authenticated user in the system. However, the authorization process would not properly check the data access operation to ensure that the authenticated user performing the operation has sufficient entitlements to perform the requested data access, hence bypassing any other authorization checks present in the system. For example, attackers can look at places where user specific data is retrieved (e.g. search screens) and determine whether the key for the item being looked up is controllable externally. The key may be a hidden field in the HTML form field, might be passed as a URL parameter or as an unencrypted cookie variable, then in each of these cases it will be possible to tamper with the key value. One manifestation of this weakness is when a system uses sequential or otherwise easily-guessable session IDs that would allow one user to easily switch to another user’s session and read/modify their data.