A flaw was found in the login-failure storage component of Keycloak, the identity and access management solution. This issue specifically affects deployments using MySQL or MariaDB databases in a multi-node configuration. When multiple failed login attempts occur simultaneously for the same account, a synchronization error can cause the system to enter a repetitive loop that locks the user's record in the database.
This results in legitimate login attempts for that user being blocked and failing with an error. Furthermore, because some failures are not correctly recorded during this loop, the system's brute-force protection may not accurately count all failed attempts.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
High
Difficult to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
Low
Partial data modification
Availability
Low
Partial disruption
CVSS Vector v3.1