According to a post by Sergey Kononenko at Exim developer mailing list, there is a possibility of remote root attack against Exim Internet Mailer in Debian package.
The possible vulnerability was in Exim from Debian Lenny (exim4-daemon-light 4.69-9) but other versions might be vulnerable. An attacker could exploit this vulnerability to gain control of a mail server.
More information is available here.
Source:[http://lists.exim.org]