CVE-2021-21396 – Bulk list client endpoint exposes too much metadata about a client

https://notcve.org/view.php?id=CVE-2021-21396

wire-server is an open-source back end for Wire, a secure collaboration platform. In wire-server from version 2021-02-16 and before version 2021-03-02, the client metadata of all users was exposed in the `GET /users/list-clients` endpoint. The endpoint could be used by any logged in user who could request client details of any other user (no connection required) as far as they can find their User ID. The exposed metadata included id, class, type, location, time, and cookie. A user on a Wire backend could use this endpoint to find registration time and location for each device for a given list of users. • https://github.com/wireapp/wire-server/commit/7ba2bf4140282557cf215e0b2c354d4d08cd3421 https://github.com/wireapp/wire-server/releases/tag/v2021-03-02 https://github.com/wireapp/wire-server/security/advisories/GHSA-qx8q-rhq2-rg4j • CWE-200: Exposure of Sensitive Information to an Unauthorized Actor •