CORS settings overly permissive in vantage6

Vulnerability Description

vantage6 is an open source framework built to enable, manage and deploy privacy enhancing technologies like Federated Learning and Multi-Party Computation. The vantage6 server has no restrictions on CORS settings. It should be possible for people to set the allowed origins of the server. The impact is limited because v6 does not use session cookies. This issue has been addressed in commit `70bb4e1d8` and is expected to ship in subsequent releases. Users are advised to upgrade as soon as a new release is available. There are no known workarounds for this vulnerability.

References

• https://github.com/vantage6/vantage6/security/advisories/GHSA-4946-85pr-fvxh
• https://github.com/vantage6/vantage6/commit/70bb4e1d889230a841eb364d6c03accd7dd01a41