lsassd in Likewise Open /Enterprise 5.3 before build 7845, Open 6.0 before build 8325, and Enterprise 6.0 before build 178, as distributed in VMware ESXi 4.1 and ESX 4.1 and possibly other products, allows remote attackers to cause a denial of service (daemon crash) via an Active Directory login attempt that provides a username containing an invalid byte sequence.