Auth bypass in Zulip
CVE-2023-32677
Zulip is an open-source team collaboration tool with unique topic-based threading. Zulip administrators can configure Zulip to limit who can add users to streams, and separately to limit who can invite users to the organization. In Zulip Server 6.1 and below, the UI which allows a user to invite a new user also allows them to set the streams that the new user is invited to -- even if the inviting user would not have permissions to add an existing user to streams. While such a configuration is likely rare in practice, the behavior does violate security-related controls. This does not let a user invite new users to streams they cannot see, or would not be able to add users to if they had that general permission. This issue has been addressed in version 6.2. Users are advised to upgrade. Users unable to upgrade may limit sending of invitations down to users who also have the permission to add users to streams.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.1 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.006 (44.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 44.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
- Zulip — versions > 1.9.0, < 6.2
Weakness classification (CWE)
References
- github.com/zulip/zulip/security/advisories/GHSA-mrvp-96q6-jpvc (Third Party Advisory)
- github.com/zulip/zulip/commit/7c2693a2c64904d1d0af8503b57763943648cbe5 (Patch, Third Party Advisory)
- zulip.com/help/configure-who-can-invite-to-streams (Product)
- zulip.com/help/restrict-account-creation (Product)
Frequently asked questions
- What is CVE-2023-32677?
- CVE-2023-32677 is a low-severity vulnerability in Zulip, classified under Missing Authorization. CVSS score: 3.1/10. Published 2023-05-19.
- How severe is CVE-2023-32677?
- Low severity. CVSS v3 base score is 3.1 out of 10.