IBM Connections 3.x before 3.0.1.1 CR3, 4.0 before CR4, 4.5 before CR5, and 5.0 before CR3 does not properly detect recursion during XML entity expansion, which allows remote attackers to cause a denial of service (CPU consumption and application crash) via a crafted XML document containing a large number of nested entity references, a similar issue to CVE-2003-1564.