[SECURITY] [DLA 393-1] srtp security update

Package : srtp
Version : 1.4.4~dfsg-6+deb6u2
CVE ID : CVE-2015-6360

Prevent potential DoS attack due to lack of bounds checking on RTP header
CSRC count and extension header length. Credit goes to Randell Jesup and
the Firefox team for reporting this issue.

(As there is no aead mode available in the Squeeze version,
only srtp_unprotect() needed to be patched)