This indicates an attack attempt to exploit an Information Disclosure vulnerability in Digium Asterisk.
The vulnerability is due to an error when the vulnerable application handles incoming RTP/RTCP messages. A remote attacker can exploit this to gain unauthorized access to sensitive information.
Digium Asterisk Open Source prior to 13.17.1
Digium Asterisk Open Source prior to 14.6.1
Digium Asterisk Open Source prior to 11.25.2
Digium Certified Asterisk prior to 11.6-cert17
Digium Certified Asterisk prior to 13.13-cert5
Information Disclosure: Remote attackers can gain sensitive information from vulnerable systems.
Apply the most recent upgrade or patch from the vendor.