CVE-2023-47642 — Zulip is an open-source team collaboration tool

Zulip is an open-source team collaboration tool. It was discovered by the Zulip development team that active users who had previously been subscribed to a stream incorrectly continued being able to use the Zulip API to access metadata for that stream. As a result, users who had b

01What is this vulnerability?

Zulip is an open-source team collaboration tool. It was discovered by the Zulip development team that active users who had previously been subscribed to a stream incorrectly continued being able to use the Zulip API to access metadata for that stream. As a result, users who had been removed from a stream, but still had an account in the organization, could still view metadata for that stream…

02Affected products

Vendor	Product	Versions
zulip	zulip	>= 1.3.0, < 7.5

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-11-16T21:41:46.646Z
• Last modified: 2024-08-29T14:49:20.515Z

09References

• github.com — https://github.com/zulip/zulip/security/advisories/GHSA-c9wc-65fh-9x8p
• github.com — https://github.com/zulip/zulip/commit/6336322d2f9bbccaacfc80cba83a3c62eefd5737