#VU69404 Information exposure through timing discrepancy in Zulip Server - CVE-2022-41914

Vulnerability identifier: #VU69404

Vulnerability risk: Medium

CVSSv4.0: 1.7 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2022-41914

CWE-ID: CWE-208

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 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

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

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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.