Microsoft Word 2003 SP3, 2007 SP3, 2010 SP1 and SP2, 2013, and 2013 RT; Word Viewer; Office Compatibility Pack SP3; Office for Mac 2011; Word Automation Services on SharePoint Server 2010 SP1 and SP2 and 2013; Office Web Apps 2010 SP1 and SP2; and Office Web Apps Server 2013 allow remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via crafted RTF data, as exploited in the wild in March 2014.
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2014/ms14-017