Format string vulnerability in exim (3.22-10 in Red Hat, 3.12 in Debian and 3.16 in Conectiva) in batched SMTP mode allows a remote attacker to execute arbitrary code via format strings in SMTP mail headers.
https://exchange.xforce.ibmcloud.com/vulnerabilities/6671
http://www.securityfocus.com/bid/2828
http://www.redhat.com/support/errata/RHSA-2001-078.html
http://www.debian.org/security/2001/dsa-058
http://distro.conectiva.com.br/atualizacoes/?id=a&anuncio=000402