The MacReadPOSTResource function in base/ftobjs.c in FreeType before 2.5.4 proceeds with adding to length values without validating the original values, which allows remote attackers to cause a denial of service (integer overflow and heap-based buffer overflow) or possibly have unspecified other impact via a crafted Mac font.
cff/cf2intrp.c in the CFF CharString interpreter in FreeType before 2.5.4 proceeds with additional hints after the hint mask has been computed, which allows remote attackers to execute arbitrary code or cause a denial of service (stack-based buffer overflow) via a crafted OpenType font. NOTE: this vulnerability exists because of an incomplete fix for CVE-2014-2240.
The ttfaceloadkern function in sfnt/ttkern.c in FreeType before 2.5.4 enforces an incorrect minimum table length, which allows remote attackers to cause a denial of service (out-of-bounds read) or possibly have unspecified other impact via a crafted TrueType font.
The ttcmap4validate function in sfnt/ttcmap.c in FreeType before 2.5.4 validates a certain length field before that field's value is completely calculated, which allows remote attackers to cause a denial of service (out-of-bounds read) or possibly have unspecified other impact via a crafted cmap SFNT table.
The bdfparseglyphs function in bdf/bdflib.c in FreeType before 2.5.4 does not properly handle a missing ENDCHAR record, which allows remote attackers to cause a denial of service (NULL pointer dereference) or possibly have unspecified other impact via a crafted BDF font.
The ttfaceloadhdmx function in truetype/ttpload.c in FreeType before 2.5.4 does not establish a minimum record size, which allows remote attackers to cause a denial of service (out-of-bounds read) or possibly have unspecified other impact via a crafted TrueType font.