vbscript.dll in VBScript 5.1, 5.6, 5.7, and 5.8 in Microsoft Windows 2000 SP4, XP SP2 and SP3, and Server 2003 SP2, when Internet Explorer is used, allows user-assisted remote attackers to execute arbitrary code by referencing a (1) local pathname, (2) UNC share pathname, or (3) WebDAV server with a crafted .hlp file in the fourth argument (aka helpfile argument) to the MsgBox function, leading to code execution involving winhlp32.exe when the F1 key is pressed, aka "VBScript Help Keypress Vulnerability."