CVE-2017-0881

Severity: medium (CVSS 4.3 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2017-03-28 · updated 2026-06-17
Weakness: CWE-200

Description

An error in the implementation of an autosubscribe feature in the check_stream_exists route of the Zulip group chat application server before 1.4.3 allowed an authenticated user to subscribe to a private stream that should have required an invitation from an existing member to join. The issue affects all previously released versions of the Zulip server.

Affected products

zulip: before 1.4.3 — fixed in 1.4.3

How to fix

Upgrade to a fixed version: zulip 1.4.3. Check the vendor advisory for mitigations.

References

http://www.securityfocus.com/bid/97159
https://github.com/zulip/zulip/commit/7ecda1ac8e26d8fb3725e954b2dc4723dda2255f
https://groups.google.com/d/msg/zulip-announce/VyawgRuoY34/NTBwnTArGwAJ
http://www.securityfocus.com/bid/97159
https://github.com/zulip/zulip/commit/7ecda1ac8e26d8fb3725e954b2dc4723dda2255f
https://groups.google.com/d/msg/zulip-announce/VyawgRuoY34/NTBwnTArGwAJ

Get alerted when CVE-2017-0881 or the next vulnerability affects your stack