{"id":"CVE-2017-0881","url":"https://www.cyber-defence.io/tools/cve/CVE-2017-0881","generatedAt":"2026-10-29T02:44:57.606Z","title":"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…","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.","published":"2017-03-28T02:59:01.000Z","lastModified":"2026-06-17T00:58:27.000Z","status":"Modified","sourceIdentifier":"support@hackerone.com","cvss":{"version":"3.0","score":4.3,"severity":"MEDIUM","vector":"CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N"},"cwe":["CWE-200","CWE-863"],"affected":["zulip/zulip server"],"epss":{"score":0.01103,"percentile":0.65552,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (1.10%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"http://www.securityfocus.com/bid/97159","tags":["Third Party Advisory","Vendor Advisory"],"source":"support@hackerone.com"},{"url":"https://github.com/zulip/zulip/commit/7ecda1ac8e26d8fb3725e954b2dc4723dda2255f","tags":["Patch","Third Party Advisory"],"source":"support@hackerone.com"},{"url":"https://groups.google.com/d/msg/zulip-announce/VyawgRuoY34/NTBwnTArGwAJ","tags":["Patch","Release Notes","Third Party Advisory"],"source":"support@hackerone.com"},{"url":"http://www.securityfocus.com/bid/97159","tags":["Third Party Advisory","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/zulip/zulip/commit/7ecda1ac8e26d8fb3725e954b2dc4723dda2255f","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://groups.google.com/d/msg/zulip-announce/VyawgRuoY34/NTBwnTArGwAJ","tags":["Patch","Release Notes","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2017-0881","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}