LdapCtx in the LDAP service in Java SE Development Kit (JDK) and Java Runtime Environment (JRE) 5.0 Update 17 and earlier; 6 Update 12 and earlier; SDK and JRE 1.3.1_24 and earlier; and 1.4.2_19 and earlier does not close the connection when initialization fails, which allows remote attackers to cause a denial of service (LDAP service hang).