Vulnerability identifier: #VU65858
Vulnerability risk: Low
CVSSv3.1: 3.8 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]
CVE-ID:
CWE-ID:
CWE-284
Exploitation vector: Network
Exploit availability: No
Vulnerable software:
Zulip Server
Web applications /
Other software
Vendor: Zulip
Description
The vulnerability allows a remote user to gain unauthorized access to otherwise restricted functionality.
The vulnerability exists due to improper access restrictions in the autosubscribe feature in the check_stream_exists route of the Zulip group chat application server. A remote user can bypass implemented security restrictions and subscribe to a private stream without the necessary invitation from the group member.
Mitigation
Install updates from vendor's website.
Vulnerable software versions
Zulip Server: 1.1.5 - 1.4.2
External links
http://www.securityfocus.com/bid/97159
http://github.com/zulip/zulip/commit/7ecda1ac8e26d8fb3725e954b2dc4723dda2255f
http://groups.google.com/d/msg/zulip-announce/VyawgRuoY34/NTBwnTArGwAJ
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.