SASL is the Simple Authentication and Security Layer, a method for adding authentication support to connection-based protocols. To use SASL, a protocol includes a command for identifying and authenticating a user to a server and for optionally negotiating protection of subsequent protocol interactions. If its use is negotiated, a security layer is inserted between the protocol and the connection.
It seems that sasldb is supposed not to be group readable. Doing
chmod 600 /etc/sasldb should fix this.