asterisk -- TLS Certificate Common name NULL byte exploit

The Asterisk project reports:

When Asterisk registers to a SIP TLS device and and
verifies the server, Asterisk will accept signed certificates
that match a common name other than the one Asterisk is
expecting if the signed certificate has a common name
containing a null byte after the portion of the common
name that Asterisk expected. For example, if Asterisk is
trying to register to www.domain.com, Asterisk will accept
certificates of the form
www.domain.com\x00www.someotherdomain.com