How are Excel and PowerPoint vulnerable?
If you do not install the update for your version of PowerPoint/Excel, your installations of Excel and PowerPoint will be vulnerable to malicious macros. An attacker could create a file that contains a macro that runs without your permission. Macros can take any action that you can take. As a result, this vulnerability could give an attacker the opportunity to take actions such as changing data, communicating with Web sites, reformatting the hard disk, or changing some security settings. By changing your security settings, an attacker could disable macro protection. If the attacker then delivered a malicious macro, your system would not be protected.
