Updated asterisk packages fix security vulnerabilities:
In Asterisk before 11.8.1, sending a HTTP request that is handled by Asterisk with a large number of Cookie headers could overflow the stack. You could even exhaust memory if you sent an unlimited number of headers in the request (CVE-2014-2286).
In Asterisk before 11.8.1, an attacker can use all available file descriptors using SIP INVITE requests. Each INVITE meeting certain conditions will leak a channel and several file descriptors. The file descriptors cannot be released without restarting Asterisk which may allow intrusion detection systems to be bypassed by sending the requests slowly (CVE-2014-2287).