The self-registration flow accepts user-supplied input for usernames without adequately preventing the disclosure of username existence. When a user attempts to register with an existing username, the system responds with an error message that explicitly indicates the username is already in use. This behavior allows an attacker to discover valid usernames within the system.
The discovery of valid usernames can facilitate subsequent attacks such as brute force, social engineering, and targeted phishing campaigns.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
Low
Partial data leak
Integrity
None
No data modification
Availability
None
No disruption
CVSS Vector v3.1
Weakness Type (CWE)
Vulnerable Products
wso2:wso2 universal gateway
wso2:wso2 carbon identity application authentication framework
wso2:wso2 open banking iam
wso2:wso2 api control plane
wso2:wso2 identity server as key manager
wso2:wso2 traffic manager
wso2:wso2 carbon identity management endpoint util
wso2:wso2 open banking am
wso2:wso2 identity server
wso2:wso2 api manager