The WPG parser in ImageMagick before 6.9.4-4 and 7.x before 7.0.1-5, when a memory limit is set, allows remote attackers to have unspecified impact via vectors related to the SetImageExtent return-value check, which trigger (1) a heap-based buffer overflow in the SetPixelIndex function or an invalid write operation in the (2) ScaleCharToQuantum or (3) SetPixelIndex functions.
The OpenBlob function in blob.c in GraphicsMagick before 1.3.24 and ImageMagick allows remote attackers to execute arbitrary code via a | (pipe) character at the start of a filename.