In affected versions of Octopus Server an Insecure Direct Object Reference vulnerability exists where it is possible for a user to download Project Exports from a Project they do not have permissions to access. This vulnerability only impacts projects within the same Space.
When generating a user invitation code in Octopus Server, the validity of this code can be set for a specific number of users. It was possible to bypass this restriction of validity to create extra user accounts above the initial number of invited users.
When Octopus Server is installed using a custom folder location, folder ACLs are not set correctly and could lead to an unprivileged user using DLL side-loading to gain privileged access.