Asterisk Project Security Advisory – Many modules in Asterisk that service incoming IP traffic have ACL options (“permit” and “deny”) that can be used to whitelist or blacklist address ranges. A bug has been discovered where the address family of incoming packets is only compared to the IP address family of the first entry in the list of access control rules. If the source IP address for an incoming packet is not of the same address family as the first ACL entry, that packet bypasses all ACL rules. For ACLs whose rules are all of the same address family, there is no issue.