Win32 API Design Error
Attackers with local access may exploit this vulnerability to elevate privileges if a window belonging to another process with higher privileges is present. A paper, entitled 'Win32 Message Vulnerabilities Redux' has been published by iDEFENSE that describes another Windows message that may be abused in a similar manner to WM_TIMER. Another proof-of-concept has been released by Brett Moore in a paper entitled 'Shattering SEH III' which demonstrates how Shatter attacks may be used against applications which make use of progress bar controls. Brett Moore has released a paper entitled 'Shattering By Example' which summarizes previous Shatter attacks, discusses new techniques and also provides an exploit which abuses Windows statusbars using WM_SETTEXT, SB_SETTEXT, SB_GETTEXTLENGTH, SB_SETPARTS and SB_GETPARTS messages.