Authorization bypass in Keycloak

1) Improper Authorization

EUVDB-ID: #VU71139

Risk: Medium

CVSSv3.1: 6.4 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2023-0091

CWE-ID: CWE-285 - Improper Authorization

Exploit availability: No

Description

The vulnerability allows a remote attacker to gain unauthorized access to the application.

The vulnerability exists due to missing authorization of a revoked token in the client-registration endpoints. A remote attacker with ability to obtain a revoked token gain unauthorized access to the application.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Keycloak: 20.0.0 - 20.0.2

External links

http://github.com/keycloak/keycloak/security/advisories/GHSA-v436-q368-hvgg

Q & A

Can this vulnerability be exploited remotely?

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

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

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