The SMB Mailslot parsing functionality in PAM in multiple ISS products with XPU (24.39/1.78/epj/x.x.x.1780), including Proventia A, G, M, Server, and Desktop, BlackICE PC and Server Protection 3.6, and RealSecure 7.0, allows remote attackers to cause a denial of service (infinite loop) via a crafted SMB packet that is not properly handled by the SMB_Mailslot_Heap_Overflow decode.