CVE-2023-28623
Published: 19 May 2023
Summary
CVE-2023-28623 is a medium-severity Improper Authorization (CWE-285) vulnerability in Zulip Zulip. Its CVSS base score is 6.5 (Medium).
Operationally, ranked at the 37.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-32291
Vulnerability details
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…
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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.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Documented procedures facilitate correct implementation and ongoing management of authorization decisions.
Periodic reviews identify and correct flaws in authorization decisions or enforcement.
Documenting permitted unauthenticated actions prevents missing authorization by making all exceptions explicit and subject to organizational review.
Establishing permitted attributes and values, plus auditing changes, ensures authorization decisions are based on correctly managed policy data.
Explicitly mandates authorizing remote access types before permitting connections, directly mitigating improper authorization.
The control explicitly requires authorization of each wireless access type prior to permitting connections.
Mandating explicit authorization of mobile device connections reduces the risk of improper authorization decisions for system access.
Specifying access authorizations for each account and requiring approvals for account requests enforces proper authorization decisions.