Vulnerability · Published May 19, 2023 · Assigned by GitHub_M
CVE-2023-28623Unauthorized user can register an account in specific configurations in Zulip
Medium 6.5
In plain English
A medium-severity missing authorization in zulip from zulip. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 45% of all known vulnerabilities).
Official description
Zulip is an open-source team collaboration tool with unique topic-based threading. In the event that 1: `ZulipLDAPAuthBackend` and an external authentication backend (any aside of `ZulipLDAPAuthBackend` and `EmailAuthBackend`) are the only ones enabled in `AUTHENTICATION_BACKENDS` in `/etc/zulip/settings.py` and 2: The organization permissions don't require invitations to join. An attacker can create a new account in the organization with an arbitrary email address in their control that's not in the organization's LDAP directory. The impact is limited to installations which have this specific combination of authentication backends as described above in addition to having `Invitations are required for joining this organization` organization permission disabled. This issue has been addressed in version 6.2. Users are advised to upgrade. Users unable to upgrade may enable the `Invitations are required for joining this organization` organization permission to prevent this issue.
Affected products (as reported)
Weakness: CWE-285, CWE-862 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
References
- https://github.com/zulip/zulip/security/advisories/GHSA-7p62-pjwg-56rv x_refsource_CONFIRM
- https://github.com/zulip/zulip/commit/3df1b4dd7c210c21deb6f829df19412b74573f8d x_refsource_MISC