MOC error on insecure configuration file

Problem

I added a configuration file for the MOC music player in my home directory: ~/.moc/config. On running mocp, it threw this error:

FATAL_ERROR: Configuration file is not secure: /home/joe/.moc/config

Solution

MOC requires that this configuration file be only writable by root or current user and nobody else. However, this file had write permissions for the users belonging to its group. MOC started without error once I removed the write permission for group:

$ chmod g-w ~/.moc/config

Tried with: MOC 2.5.0 and Ubuntu 14.04