Format string vulnerability in the ext_yahoo_contact_added function in yahoo.c in Miranda IM 0.7.1 allows remote attackers to execute arbitrary code via a Y7 Buddy Authorization packet with format string specifiers in the contact Yahoo! handle (who).
https://exchange.xforce.ibmcloud.com/vulnerabilities/38362
http://www.vupen.com/english/advisories/2007/3823
http://www.securityfocus.com/bid/26389
http://secunia.com/secunia_research/2007-89/advisory/