Randell Jesup and the Firefox team discovered that srtp, Cisco's reference implementation of the Secure Real-time Transport Protocol (SRTP), does not properly handle RTP header CSRC count and extension header length. A remote attacker can exploit this vulnerability to crash an application linked against libsrtp, resulting in a denial of service.
References:
http://seclists.org/bugtraq/2016/Apr/11
Cisco IP Phone (VoIP) 7920 1.0(8) contains certain hard-coded ("fixed") public and private SNMP community strings that cannot be changed, which allows remote attackers to obtain sensitive information.