Encrypting db password stored in settings.php The db password in settings.php is stored as plain text.
Is there any way to encrypt that password?

My client says its a security risk even though the file permissions is as should.
This is not a Drupal question specifically. Depending on the OWASP security standards you're following keeping the password in plain in settings.php could be considered a risk (in a normal, usual Drupal environment it won't be the case)

This thread on Information Security Stack Exchange discusses the topic, but in my opinion is a little paranoid and most of the options will slow down your site.