Adobe Acrobat Reader versions 11.0.19 and earlier, 15.006.30280 and earlier, 15.023.20070 and earlier have an exploitable memory corruption vulnerability when parsing TTF (TrueType font format) stream data. Successful exploitation could lead to arbitrary code execution.
https://helpx.adobe.com/security/products/acrobat/apsb17-24.html
https://helpx.adobe.com/security/products/acrobat/apsb17-11.html
http://www.securitytracker.com/id/1039098