The sysctl functionality (sysctl.c) in Linux kernel before 2.6.14.1 allows local users to cause a denial of service (kernel oops) and possibly execute code by opening an interface file in /proc/sys/net/ipv4/conf/, waiting until the interface is unregistered, then obtaining and modifying function pointers in memory that was used for the ctl_table.
http://secunia.com/advisories/17504
http://secunia.com/advisories/17541
http://secunia.com/advisories/17648
http://secunia.com/advisories/18510
http://secunia.com/advisories/18562
http://secunia.com/advisories/18684
http://secunia.com/advisories/19369
http://secunia.com/advisories/19374
http://securitytracker.com/id?1015434
https://exchange.xforce.ibmcloud.com/vulnerabilities/23040
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10746
http://www.debian.org/security/2006/dsa-1017
http://www.debian.org/security/2006/dsa-1018
http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.14.1
http://www.mandriva.com/security/advisories?name=MDKSA-2006:059
http://www.redhat.com/support/errata/RHSA-2006-0101.html
http://www.redhat.com/support/errata/RHSA-2006-0140.html
http://www.redhat.com/support/errata/RHSA-2006-0190.html