Apple Xserve Lights-Out Management before Firmware Update 1.0 on Intel hardware does not require a password for remote access to IPMI, which allows remote attackers to gain administrative access via unspecified requests with ipmitool.
https://exchange.xforce.ibmcloud.com/vulnerabilities/34651
http://www.vupen.com/english/advisories/2007/2014
http://www.securitytracker.com/id?1018181
http://www.securityfocus.com/bid/24257
http://www.apple.com/support/downloads/xservelightsoutmanagementfirmwareupdate10.html
http://secunia.com/advisories/25499
http://lists.apple.com/archives/security-announce/2007/May/msg00006.html