Mail accounts cannot log into Plesk web interface if password is encrypted

Symptoms

• Mail accounts with Access to the Control Panel option set in Domains > example.com > Email Addresses > mailbox name cannot log into Plesk GUI with PLAIN password if the password is encrypted in the database. The following error is displayed:
  

  PLESK_ERROR: Error: You have entered incorrect username or password.

• The users had an encrypted password before the upgrade:

  # mysql -uadmin -p`cat /etc/psa/.psa.shadow` -Dpsa -e "select mail_name, domains.name as domain from accounts, mail,domains where dom_id = domains.id and mail.account_id = accounts.id and type='crypt'"
  +-----------+--------+
  | mail_name | domain |
  +-----------+--------+
  | admin | example.com |
  +-----------+--------+

• PLAIN authentication to the mail server itself works without issues, only Plesk GUI login does not work.

Cause

This is a bug with ID PPPM-1405 which is planned to be fixed in future Plesk updates.

Resolution

1. Connect to the server using SSH.
2. Get a list of mail users with encrypted passwords (affected users):

   # mysql -uadmin -p`cat /etc/psa/.psa.shadow` -Dpsa -e "select mail_name, domains.name as domain from accounts, mail,domains where dom_id = domains.id and mail.account_id = accounts.id and type='crypt'"
   +-----------+--------+
   | mail_name | domain |
   +-----------+--------+
   | admin | example.com |
   +-----------+--------+

3. Change the password for all users retrieved from the list in Domains > example.com > Email Addresses > mailbox name.

As a workaround for Plesk 12.5 and Plesk Onyx, use:

1. Apply custom fix:
   For RHEL/CentOS:
   

   # wget https://plesk.zendesk.com/hc/article_attachments/115003198434/User.zip
   # unzip User.zip
   # mv /usr/local/psa/admin/plib/Smb/Db/Table/Row/User.php{,.bk}
   # mv User.php /usr/local/psa/admin/plib/Smb/Db/Table/Row/User.php

   For Debian/Ubuntu:
   

   # wget https://plesk.zendesk.com/hc/article_attachments/115003198434/User.zip
   # unzip User.zip
   # mv /opt/psa/admin/plib/Smb/Db/Table/Row/User.php{,.bk}
   # mv User.php /opt/psa/admin/plib/Smb/Db/Table/Row/User.php

   Note: For Plesk 12.5 the custom fix can be applied without password changing.