CVE-2023-47642 Stream description leaks to ex-subscribers in Zulip

Medium 4.3 Published 16 Nov 2023 Updated 29 Aug 2024

Former stream subscribers can access restricted stream metadata, including names and settings, due to improper access control checks.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2023-47642?

CVE-2023-47642 is a medium-severity vulnerability in zulip, published on 16 Nov 2023. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

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 (including the stream name, description, settings, and an email address used to send emails into the stream via the incoming email integration). This potentially allowed users to see changes to a stream’s metadata after they had lost access to the stream. This vulnerability has been addressed in version 7.5 and all users are advised to upgrade. There are no known workarounds for this issue.

Weakness: CWE-200

Which versions are affected by CVE-2023-47642?

It affects 1 product.

Products include Zulip Zulip Server.

How do I fix CVE-2023-47642?

No fix has been published for CVE-2023-47642 yet. Limit exposure of the affected software until one is available.

Is CVE-2023-47642 being exploited?

There is no known exploitation of CVE-2023-47642 in the wild and no public exploit code.

Sources

Also known as GHSA-c9wc-65fh-9x8p.