Actual is a local-first personal finance tool. Prior to version 26.2.1, in multi-user mode (OpenID), the sync API endpoints (/sync/*) dont verify that the authenticated user owns or has access to the file being operated on. Any authenticated user can read, modify, and overwrite any other users budget files by providing their file ID. Version 26.2.1 patches the issue.
Weakness
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Actual | Actualbudget | * | 26.2.1 (excluding) |
Potential Mitigations
- Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries.
- Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
- For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page.
- One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.