IBM WebSphere Application Server (WAS) 7.x before 7.0.0.43, 8.0.0.x before 8.0.0.13, 8.5.0.x before 8.5.5.10, 8.5.0.x and 16.0.0.x Liberty before Liberty Fix Pack 16.0.0.3, and 9.0.0.x before 9.0.0.1 allows remote attackers to cause a denial of service via crafted SIP messages.