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ECP SAML binding bypasses authentication flows

High severity GitHub Reviewed Published Apr 25, 2022 in keycloak/keycloak • Updated Jan 27, 2023

Package

maven org.keycloak:keycloak-saml-core (Maven)

Affected versions

< 18.0.0

Patched versions

18.0.0

Description

Description

A flaw was found in keycloak, where the default ECP binding flow allows other authentication flows to be bypassed. By exploiting this behavior an attacker can bypass the MFA authentication by sending a SOAP request with an AuthnRequest and Authorization header with the user's credentials. The highest threat from this vulnerability is to confidentiality and integrity.

References

@abstractj abstractj published to keycloak/keycloak Apr 25, 2022
Published to the GitHub Advisory Database Apr 27, 2022
Reviewed Apr 27, 2022
Published by the National Vulnerability Database Aug 23, 2022
Last updated Jan 27, 2023

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

EPSS score

0.156%
(53rd percentile)

Weaknesses

CVE ID

CVE-2021-3827

GHSA ID

GHSA-4pc7-vqv5-5r3v

Source code

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