Error
Error Code:
3878
MySQL Error 3878: Empty Second Password Not Allowed
Description
This error indicates an attempt to assign an empty string as the 'second password' for a MySQL user. MySQL requires the 'second_password' field, often used for specific authentication plugins or multi-factor authentication, to contain a non-empty value.
Error Message
Empty password can not be retained as second password for user '%s'@'%s'.
Known Causes
3 known causesDirect Assignment of Empty Password
The most common cause is explicitly trying to set an empty string as the `second_password` for a user via SQL commands or client tools.
Misconfigured Authentication Plugin
An authentication plugin requiring a `second_password` might be configured to provide an empty value, leading to this error during user management operations.
Application or Scripting Error
Automated scripts or applications managing MySQL users may contain logic errors that inadvertently pass an empty string for the second password field.
Solutions
3 solutions available1. Assign a Non-Empty Second Password easy
Update the user account to have a valid, non-empty second password.
1
Connect to your MySQL server with a user that has privileges to modify user accounts (e.g., root).
2
Execute the `ALTER USER` statement to set a new, non-empty password for the affected user. Replace `'username'` and `'hostname'` with the actual user and host, and `'new_secure_password'` with a strong password.
ALTER USER 'username'@'hostname' IDENTIFIED WITH mysql_native_password BY 'new_secure_password';
-- If you are using a different authentication plugin, adjust accordingly.3
If the user has multiple authentication methods configured and you intend to set a second password for a specific method (e.g., `caching_sha2_password`), you might need to specify it.
ALTER USER 'username'@'hostname' IDENTIFIED WITH caching_sha2_password BY 'new_secure_password';4
Verify the change by attempting to connect with the specified user and the new password.
2. Remove the Second Password Configuration easy
If a second password is not required, remove its association with the user account.
1
Connect to your MySQL server with appropriate administrative privileges.
2
Execute the `ALTER USER` statement to reset the user's password, effectively removing any second password configuration. Replace `'username'` and `'hostname'` with the actual user and host, and `'current_or_new_password'` with the desired password (can be empty if allowed for the primary password, but the error implies the second password was the issue).
ALTER USER 'username'@'hostname' IDENTIFIED BY 'current_or_new_password';
-- This command often resets the primary password and implicitly removes secondary password configurations if they were problematic.3
If you are using specific authentication plugins and want to ensure no secondary password is set, you might need to explicitly remove it. This is less common as `IDENTIFIED BY` usually handles it. However, if you have complex configurations, you might need to consult MySQL documentation for specific plugin management.
4
Test the user's login to confirm the issue is resolved.
3. Update MySQL Server Configuration (Advanced) advanced
Modify MySQL server settings to allow or disallow empty second passwords (use with extreme caution).
1
Locate your MySQL server's configuration file (e.g., `my.cnf`, `my.ini`). The location varies by operating system and installation method.
2
Open the configuration file in a text editor with administrative privileges.
3
Look for a section related to user accounts or authentication. There isn't a direct global setting to 'allow empty second passwords' as it's generally a security risk. The error 3878 specifically prevents it. This solution is more about understanding why it's disallowed and potentially reconfiguring authentication plugins if you have a very specific use case that deviates from standard security practices.
4
If you are encountering this error in a non-standard setup or a very old MySQL version, you might investigate plugin-specific configurations. However, for modern MySQL versions, the intent is to prevent insecure password practices. The most practical approach remains to set a valid second password or remove its requirement.
5
If you've made changes to the configuration file, restart the MySQL server for the changes to take effect.
sudo systemctl restart mysql # For systemd-based systems
# or
sudo service mysql restart # For older init systems