CVE-2021-21396 Bulk list client endpoint exposes too much metadata about a client
Logged-in users can access sensitive client metadata of other users via an exposed endpoint, requiring an upgrade to the Wire backend server.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-21396?
CVE-2021-21396 is a medium-severity vulnerability in wireapp wire-server, published on 26 Mar 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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. As a workaround, remove `/list-clients` from nginx config. This has been fixed in version 2021-03-02.
Weakness: CWE-200
Which versions are affected by CVE-2021-21396?
It affects 1 product.
Products include Wire Wire Server.
How do I fix CVE-2021-21396?
No fix has been published for CVE-2021-21396 yet. Limit exposure of the affected software until one is available.
Is CVE-2021-21396 being exploited?
There is no known exploitation of CVE-2021-21396 in the wild and no public exploit code.
Other vulnerabilities in wireapp wire-server
Sources
Also known as GHSA-qx8q-rhq2-rg4j.