Format string vulnerability in ANSI C Sender Policy Framework library (libspf) before 1.0.0-p5, when debugging is enabled, allows remote attackers to execute arbitrary code via format string specifiers, possibly in an e-mail address.
https://exchange.xforce.ibmcloud.com/vulnerabilities/26535
http://www.vupen.com/english/advisories/2006/1846
http://www.libspf.org/index.html
http://www.gossamer-threads.com/lists/spf/devel/27053?page=last