Untrusted search path vulnerability in Microsoft Excel 2007 SP3, Excel 2010 SP2, Excel Viewer 2007 SP3, and Office Compatibility Pack SP3 allows local users to gain privileges via a Trojan horse DLL in the current working directory, aka "Microsoft Excel DLL Remote Code Execution Vulnerability."
https://euvd.enisa.europa.eu/vulnerability/EUVD-2015-2471
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2015/ms15-070