The FT_Stream_EnterFrame function in base/ftstream.c in FreeType before 2.4.2 does not properly validate certain position values, which allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted font file.
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.