Microsoft Office and Microsoft Windows RichEdit component are prone to a remote code-execution vulnerability. This issue occurs when malformed Rich Text Files (RTF) are processed. An attacker could exploit this issue by enticing a victim to load a malicious RTF file. If the vulnerability is successfully exploited, this could result in the execution of arbitrary code in the context of the currently logged-in user.
Microsoft has released security advisory MS07-013 to address this issue. Please see the references for more information.