Home/CVE/Zulip is an open-source team collaboration tool with unique topic-based threading. In the event that 1: `ZulipLDAPAuthBa
CVE

CVE-2023-28623

Zulip is an open-source team collaboration tool with unique topic-based threading. In the event that 1: `ZulipLDAPAuthBa

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.

MEDIUM · CVSS 6.5 EPSS 0.00169
Monitor
  • No active-exploitation, high-EPSS, or public-exploit signals - routine patching cadence
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-285Improper Authorization
CWE-862Missing Authorization
CWE-862Missing Authorization
▤

Affected Products & Versions

1
zulip< 6.2
▣

Scoring & Timeline

6.5
MEDIUM · CVSS v3.1 · security-advisories@github.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD19 May 2023 · 10:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
no
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
🔗

References & Sources

2
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://github.com/zulip/zulip/commit/3df1b4dd7c210c21deb6f829df19412b74573f8dPatchThird Party Advisory
https://github.com/zulip/zulip/security/advisories/GHSA-7p62-pjwg-56rvThird Party Advisory
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