asterisk -- Multiple Vulnerabilities

Asterisk project reports:

It is possible to enumerate SIP usernames when the general and
user/peer NAT settings differ in whether to respond to the port
a request is sent from or the port listed for responses in the
Via header.

When the “automon” feature is enabled in features.conf, it is
possible to send a sequence of SIP requests that cause Asterisk
to dereference a NULL pointer and crash.