Internet Explorer on Windows Mobile 5.0 and Windows Mobile 2003 and 2003SE for Smartphones and PocketPC allows attackers to cause a denial of service (application crash and device instability) via unspecified vectors, possibly related to a buffer overflow.
https://exchange.xforce.ibmcloud.com/vulnerabilities/32001
http://www.vupen.com/english/advisories/2007/0434
http://www.securityfocus.com/bid/22343
http://blog.trendmicro.com/trend-micro-finds-more-windows-mobile-flaws/