Permissions, Privileges, and Access Controls
The new_password page in PBBoard 2.1.4 allows remote attackers to change the password of arbitrary user accounts via the member_id and new_password parameters to index.php.
CWE-264 - Permissions Privileges and Access Controls
CWE 264 (permissions, privileges, and access controls) is not a weakness in and of itself, rather it is a category of weaknesses related to the management of permissions, privileges, and other security features used to perform access control. If not addressed, the weaknesses in this category allow attackers to gain privileges for an unintended sphere of control, access sensitive information, and execute arbitrary commands.