#VU59892 Authentication bypass using an alternate path or channel in Keycloak - CVE-2021-3827

Vulnerability identifier: #VU59892

Vulnerability risk: Medium

CVSSv4.0: 4.9 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-3827

CWE-ID: CWE-288

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 bypass 2FA authentication.

The vulnerability exists due to an error in ECP SAML binding flow within keycloak-server-spi-private. A remote attacker can send SOAP request with an AuthnRequest and Authorization header with the user's credentials and bypass MFA authentication.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Keycloak: 15.0.0 - 15.1.1

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External links
https://bugzilla.redhat.com/show_bug.cgi?id=2007512

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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.