Memory leak in Cisco Unified Communications Manager (aka CUCM, formerly CallManager) 6.x before 6.1(5)su3, 7.x before 7.1(5b)su3, 8.0 before 8.0(3a)su2, and 8.5 before 8.5(1) allows remote attackers to cause a denial of service (memory consumption and process failure) via a malformed SIP message, aka Bug ID CSCti42904.