Updated dhcp packages that fix two security issues are now available for Red Hat Enterprise Linux 3. This update has been rated as having critical security impact by the Red Hat Security Response Team.
The Dynamic Host Configuration Protocol (DHCP) is a protocol that allows individual devices on an IP network to get their own network configuration information, including an IP address, a subnet mask, and a broadcast address. The Mandriva Linux Engineering Team discovered a stack-based buffer overflow flaw in the ISC DHCP client. If the DHCP client were to receive a malicious DHCP response, it could crash or execute arbitrary code with the permissions of the client (root). (CVE-2009-0692) An insecure temporary file use flaw was discovered in the DHCP daemon's init script ("/etc/init.d/dhcpd"). A local attacker could use this flaw to overwrite an arbitrary file with the output of the "dhcpd -t" command via a symbolic link attack, if a system administrator executed the DHCP init script with the "configtest", "restart", or "reload" option. (CVE-2009-1893) Users of DHCP should upgrade to these updated packages, which contain backported patches to correct these issues.