util-vserver before 0.30.208-1 with kernel-patch-vserver before 1.9.5.5 and 2.x before 2.3 for Debian GNU/Linux sets a default policy that trusts unknown capabilities, which could allow local users to conduct unauthorized activities.

vserver in util-vserver 0.30.209 executes a command as root when the suexec userid parameter is invalid and non-numeric, which might cause local users to inadvertently execute dangerous commands as root.