Cisco Unified Communications Manager (CUCM) 5.x before 5.1(2) and 6.x before 6.1(1) allows remote attackers to cause a denial of service (service interruption) via a SIP JOIN message with a malformed header, aka Bug ID CSCsi48115.

More... (http://nvd.nist.gov/nvd.cfm?cvename=CVE-2008-1745)