Sure it is possible.
Depending on what access controls are set in your server you can:
- make sure that no aci grant write access to the password (userPassword attribute).
- create aci that deny write access to the password (although I would recommend the first solution. Deny aci are difficult to manage and explain as they are creating exceptions to the access granted. Also when removing a deny ACI, rights are not removed, the opposite rights are in fact granted, reducing the overall security.
Regardsm
Ludovic.