fetchmail -- remote code injection vulnerability

fetchmail's POP3/UIDL code does not truncate received UIDs properly. A malicious or compromised POP3 server can thus corrupt fetchmail's stack and inject code when fetchmail is using UIDL, either through configuration, or as a result of certain server capabilities. Note that fetchmail is run as root on some sites, so an attack might compromise the root account and thus the whole machine.