Information disclosure in Zulip Server

1) Information exposure through timing discrepancy

EUVDB-ID: #VU69404

Risk: Medium

CVSSv3.1: 4.2 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2022-41914

CWE-ID: CWE-208 - Information Exposure Through Timing Discrepancy

Exploit availability: No

Description

The vulnerability allows a remote attacker to gain access to sensitive information.

The vulnerability exists due to a weak generation mechanism of SCIM bearer tokens. A remote attacker can infer the value of the SCIM bearer token by performing a sophisticated timing analysis on a large number of failing requests. If successful, this would allow the attacker to impersonate the SCIM client for its abilities to read and update user accounts in the Zulip organization.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Zulip Server: 5.0 - 5.6

External links

http://github.com/zulip/zulip/security/advisories/GHSA-q5gx-377v-w76f
http://github.com/zulip/zulip/commit/59edbfa4113d140d3e20126bc65f4d67b2a8ffe5

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.