An issue was discovered in icoutils 0.31.1. A buffer overflow was observed in the "extract_icons" function in the "extract.c" source file. This issue can be triggered by processing a corrupted ico file and will result in an icotool crash.
https://security.gentoo.org/glsa/201801-12
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=854054
http://www.securityfocus.com/bid/96288