Virtual Private Server (Vserver) 2.0.x before 2.0.2-rc18 and 2.1.x before 2.1.1-rc18 provides certain context capabilities (ccaps) that allow local guest users to perform operations that were only intended to be allowed by the guest-root.
https://exchange.xforce.ibmcloud.com/vulnerabilities/26285
http://www.vupen.com/english/advisories/2006/1661
http://www.securityfocus.com/bid/17842
http://www.debian.org/security/2006/dsa-1060
http://secunia.com/advisories/20206