#VU71139 Improper Authorization in Keycloak - CVE-2023-0091

Vulnerability identifier: #VU71139

Vulnerability risk: Medium

CVSSv4.0: 6.9 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2023-0091

CWE-ID: CWE-285

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Keycloak
Server applications / Directory software, identity management

Vendor: Keycloak

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

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External links
https://github.com/keycloak/keycloak/security/advisories/GHSA-v436-q368-hvgg

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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.