ISC dhclient < 3.1-ESV-R1 / 4.1-ESV-R2 / 4.2.1-P1 Remote Code Execution

ISC dhclient did not strip or escape certain shell meta-characters in responses from the dhcp server (like hostname) before passing the responses on to dhclient-script. Depending on the script and OS, this can result in execution of exploit code on the client.