Virtualisation can bring with it unanticipated security risks, because, in an unchecked, unmonitored virtual environment, administrators are all-powerful.
"This gives server admins the keys to the kingdom, and most of the time they don't understand the security risks," says Vauda Jordan, senior security engineer for the Phoenix city government. As companies turn more of their critical applications over to virtual servers, some IT managers are starting to worry about the security risks of virtualisation. For example, administrators may create a virtual FTP server that compromises security. Or they may inadvertently use a virtual-machine migration tool to move a server onto different hardware for maintenance reasons, without realising that the new host is on an untrusted network segment. Failure to implement best practices, or to establish a clear separation of duties in virtual infrastructure, is an all-too-common problem, says Andrew Mulé, a senior security consultant at RSA. "Folks still today don't like to practice segregation of duties. They give the crown jewels to a small number of people," Mulé says. He recommends developing a strong change-management process that includes issuing change management tickets. KC Condit, senior director of information security at Rent-A-Center, agrees. "In the virtual world, there is no inherent separation of duties, so you have to build that in," he says. Change management, configuration management and access control are vital to securing the virtual infrastructure. Compliance is another concern. As director of systems engineering at the Council of Europe Development Bank, Jean-Louis Nguyen needs to monitor activity to ensure that the administrators of 140 virtual machines comply with regulations and management requirements. The bank tried using VMware's logging capabilities but needed a better way to consolidate the information. "Getting at those logs was nontrivial," he says. He ended up using a dedicated tool from HyTrust that provides a central log of all activity. The bank also used HyTrust to set up a completely segregated virtual environment for the chief security officer, who can monitor the entire physical and virtual server infrastructure. "The key is to assure your management that there's no administrator abuse," Nguyen says. "We needed to be certain that we're administering systems and not peeking into the data."