Vulnerability identifier: #VU60898

Vulnerability risk: Medium

CVSSv3.1: 5.9 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C]

CVE-ID: CVE-2021-3967

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 attacker to gain unauthorized access to otherwise restricted functionality.

The vulnerability exists due to improper access restrictions. A remote user who gets the user's valid session can call vulnerable API to extract the api_key value without user's password.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Zulip Server: 1.1.5 - 4.9

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External links
http://huntr.dev/bounties/2928a625-0467-4a0a-b4e2-e27322786686
http://github.com/zulip/zulip/commit/d5db254ca8167995a1654d1c45ffc74b2fade39a

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Q & A

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. However, proof of concept for this vulnerability is available.