Format string vulnerability in the dkim_exim_verify_finish function in src/dkim.c in Exim before 4.76.
Checks for a format string vulnerability in the Exim SMTP server (version 4.70 through 4.75) with DomainKeys Identified Mail (DKIM) support (CVE-2011-1764). The DKIM logging mechanism did not use format string specifiers when logging some parts of the DKIM-Signature header field. A remote attacker who is able to send emails, can exploit this vulnerability and execute arbitrary code with the privileges of the Exim daemon.
It is recommended to upgrade your Exim MTA to the latest patches.