CVE-2023-28623 Unauthorized user can register an account in specific configurations in Zulip
Attackers can register unauthorized accounts in Zulip when specific LDAP and external authentication backends are enabled without invitation requirements.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2023-28623?
CVE-2023-28623 is a medium-severity authentication bypass vulnerability in zulip, published on 19 May 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
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.
Which versions are affected by CVE-2023-28623?
It affects 1 product.
Products include Zulip Zulip.
How do I fix CVE-2023-28623?
No fix has been published for CVE-2023-28623 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2023-28623 being exploited?
There is no known exploitation of CVE-2023-28623 in the wild and no public exploit code.
Other vulnerabilities in zulip
- CVE-2021-43799 RabbitMQ exposes ports with weak default secrets in Zulip Server
- CVE-2022-35962 Crafted link in Zulip message can cause disclosure of credentials
- CVE-2016-4427 Auth bypass in zulip
- CVE-2021-3866 Cross-site Scripting (XSS) - Stored in zulip/zulip
- CVE-2021-43791 Ineffective expiration validation for invitation links in Zulip
Sources
Also known as GHSA-7p62-pjwg-56rv.