net/core/ethtool.c in the Linux kernel before 2.6.36 does not initialize certain data structures, which allows local users to obtain potentially sensitive information from kernel heap memory by leveraging the CAP_NET_ADMIN capability for an ethtool ioctl call.
https://lkml.org/lkml/2010/10/7/297
https://bugzilla.redhat.com/show_bug.cgi?id=672428
http://www.vmware.com/security/advisories/VMSA-2011-0012.html
http://www.ubuntu.com/usn/USN-1146-1
http://www.securityfocus.com/bid/45972
http://www.securityfocus.com/archive/1/520102/100/0/threaded
http://openwall.com/lists/oss-security/2011/01/28/1
http://openwall.com/lists/oss-security/2011/01/25/5
http://openwall.com/lists/oss-security/2011/01/25/4
http://openwall.com/lists/oss-security/2011/01/25/3