You can change/reset your CUNET password yourself by setting up a security question to reset the password.
CUNET Account Management Service allows users to change and reset a password by setting a security question.
Staff and students
If the password is working but you wish to change it: https://userportal.it.chula.ac.th
Staff and students
If the password is working but you wish to change it: https://userportal.it.chula.ac.th