Microsoft has just released two (2) security bulletins.
Permissive Windows Services DACLs Could Allow Elevation of Privilege (914798)
A privilege elevation vulnerability exists on Windows XP Service Pack 1 on the identified Windows services where the permissions are set by default to a level that may allow a low-privileged user to change properties associated with the service. On Windows 2003 permissions on the identified services are set to a level that may allow a user that belongs to the network configuration operators group to change properties associated with the service. Only members of the Network Configuration Operators group on the targeted machine can remotely attack Windows Server 2003, and this group contains no users by default. The vulnerability could allow a user with valid logon credentials to take complete control of the system on Microsoft Windows XP Service Pack 1.MS06-012 (Critical)
Vulnerabilities in Microsoft Office Could Allow Remote Code Execution (905413)
…if a user is logged on with administrative user rights, an attacker who successfully exploited this vulnerability could take complete control of the client workstation. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights.
Please follow the links above for further details about the vulnerabilities and the patches for the affected products.