Format string vulnerability in send_message.c for Sylpheed-claws 0.9.4 through 0.9.6 allows remote SMTP servers to cause a denial of service (crash) in sylpheed via format strings in an error message.
https://exchange.xforce.ibmcloud.com/vulnerabilities/13508
http://www.securityfocus.com/bid/8877
http://www.guninski.com/sylph.html
http://sylpheed.good-day.net/#changes
http://lists.grok.org.uk/pipermail/full-disclosure/2003-October/012542.html