Heap-based buffer overflow in winhlp32.exe in Windows NT, Windows 2000 through SP4, Windows XP through SP2, and Windows 2003 allows remote attackers to execute arbitrary code via a crafted .hlp file.
https://exchange.xforce.ibmcloud.com/vulnerabilities/18678
https://euvd.enisa.europa.eu/vulnerability/EUVD-2004-1303
http://www.xfocus.net/flashsky/icoExp/