Description

Zulip is an open-source team collaboration tool. A vulnerability in version 8.0 is similar to CVE-2023-32677, but applies to multi-use invitations, not single-use invitation links as in the prior CVE. Specifically, it applies when the installation has configured non-admins to be able to invite users and create multi-use invitations, and has also configured only admins to be able to invite users to streams. As in CVE-2023-32677, this does not let users invite new users to arbitrary streams, only to streams that the inviter can already see. Version 8.1 fixes this issue. As a workaround, administrators can limit sending of invitations down to users who also have the permission to add users to streams.

Classification

CVE ID: CVE-2024-21630

CVSS Base Severity: MEDIUM

CVSS Base Score: 4.3

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Affected Products

Vendor: zulip

Product: zulip

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.11% (probability of being exploited)

EPSS Percentile: 30.19% (scored less or equal to compared to others)

EPSS Date: 2025-06-17 (when was this score calculated)

Stakeholder-Specific Vulnerability Categorization (SSVC)

SSVC Exploitation: none

SSVC Technical Impact: partial

SSVC Automatable: false

References

https://nvd.nist.gov/vuln/detail/CVE-2024-21630
https://github.com/zulip/zulip/security/advisories/GHSA-87p9-wprh-7rm6
https://github.com/zulip/zulip/security/advisories/GHSA-mrvp-96q6-jpvc
https://github.com/zulip/zulip/commit/0df7bd71f32f3b772e2646c6ab0d60c9b610addf
https://zulip.com/help/configure-who-can-invite-to-streams
https://zulip.com/help/restrict-account-creation#change-who-can-send-invitations

Timeline