In ImageMagick, a crafted file could trigger an assertion failure when a call to WriteImages was made in "MagickWand/operation.c", due to a NULL image list. This could potentially cause a denial of service. This was fixed in upstream ImageMagick version 7.1.0-30.
CWE-617 - Reachable Assertion
The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.