CVE-2021-21396
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.
Does this matter?
Lower severity and a low EPSS score (1.21%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
- EPSS
- 1.21% probability · 68th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-200
- Affected
- wire/wire server
- Source
- security-advisories@github.com
EPSS 1.2% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/wireapp/wire-server/commit/7ba2bf4140282557cf215e0b2c354d4d08cd3421Patch, Third Party Advisory
- https://github.com/wireapp/wire-server/releases/tag/v2021-03-02Third Party Advisory
- https://github.com/wireapp/wire-server/security/advisories/GHSA-qx8q-rhq2-rg4jPatch, Third Party Advisory
- https://github.com/wireapp/wire-server/commit/7ba2bf4140282557cf215e0b2c354d4d08cd3421Patch, Third Party Advisory
- https://github.com/wireapp/wire-server/releases/tag/v2021-03-02Third Party Advisory
- https://github.com/wireapp/wire-server/security/advisories/GHSA-qx8q-rhq2-rg4jPatch, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.