CVE-2024-21630: zulip server Auth Bypass — Fix

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.

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CVSS v3.1 Score

4.3

MEDIUM

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

Weakness Type (CWE)

CWE-862 Missing Authorization

Affected Products

Vendor	Product	Versions
zulip	zulip_server	1.9.0 — 6.2
zulip	zulip_server	8.0 — 8.1

References

Advisories & Patches

https://github.com/zulip/zulip/commit/0df7bd71f32f3b772e2646c6ab0d60c9b610addf 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://github.com/zulip/zulip/security/advisories/GHSA-87p9-wprh-7rm6 https://github.com/zulip/zulip/security/advisories/GHSA-mrvp-96q6-jpvc

Other References

https://zulip.com/help/configure-who-can-invite-to-streams https://zulip.com/help/restrict-account-creation#change-who-can-send-invitations https://zulip.com/help/configure-who-can-invite-to-streams https://zulip.com/help/restrict-account-creation#change-who-can-send-invitations

Frequently Asked Questions

What is CVE-2024-21630? +

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. It has a CVSS v3.1 base score of 4.3 (MEDIUM).

How severe is CVE-2024-21630? +

CVE-2024-21630 has a CVSS v3.1 score of 4.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2024-21630? +

CVE-2024-21630 affects products from zulip, specifically: zulip_server. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2024-21630? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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