Microsoft Publisher 2003 SP3 does not properly handle NULL values for unspecified data items, which allows remote attackers to execute arbitrary code via a crafted Publisher file, aka "Publisher Incorrect NULL Value Handling Vulnerability."
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A16733
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2013/ms13-042