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Problem With Roles: Privilege Escalation

Tags

  • type: bug
  • status: open
  • priority: critical
  • assigned: fredm, zachs
  • keywords: gn-auth, authorisation, authorization, roles, privileges

Description

The current implementation of `gn2.wqflask.oauth2.roles.create_role(???)` function is broken and can lead to possibly unbounded privilege escalation.

What it currently does is that it fetches all the roles a user has, on all resources, regardless of type and/or ownership, then allows the user to create a role from that. As such, a user with write access to ResourceA and no write access to ResourceB could hypothetically gain write access to ResourceB, by say:

  • Create a new throw-away account
  • Creating a new role, that includes the write access from ResourceA
  • Assign new role to throw-away account on ResourceB
  • Do unapproved writes on ResourceB with throw-away account

The implementation should instead, tie the roles to the specific resource, rather than group. This means, then, that the user cannot create a role on any resource that exceeds their access level for that resource ??? thus no privilege escalation is possible.

Plan of Action

  • [x] Remove the `???.create_action` function: raise exception when used
  • [x] Remove the "Roles" page on the UI
  • [x] migration: Remove `group:role:[create|delete|edit]-role` privileges from `group-leader` role
  • [x] migration: Add `resource:role:[create|delete|edit]-role` privileges to `resource-owner` role
  • [x] migration: Create new `resource_roles` db table linking each resource to roles that can act on it, and the user that created the role
  • [x] migration: Drop table `group_roles` deleting all data in the table: data here could already have privilege escalation in place
  • [ ] Create a new "Roles" section on the "Resource-View" page, or a separate "Resource-Roles" page to handle the management of that resource's roles
  • [ ] Ensure user can only assign roles they have created - maybe?

Fixes

(made with skribilo)