Heap-based buffer overflow in the Lookup_MarkMarkPos function in the HarfBuzz module (harfbuzz-gpos.c), as used by Qt before 4.7.4 and Pango, allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a crafted font file.
Heap-based buffer overflow in the pango_ft2_font_render_box_glyph function in pango/pangoft2-render.c in libpango in Pango 1.28.3 and earlier, when the FreeType2 backend is enabled, allows user-assisted remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted font file, related to the glyph box for an FT_Bitmap object.
Array index error in the hb_ot_layout_build_glyph_classes function in pango/opentype/hb-ot-layout.cc in Pango before 1.27.1 allows context-dependent attackers to cause a denial of service (application crash) via a crafted font file, related to building a synthetic Glyph Definition (aka GDEF) table by using this font's charmap and the Unicode property database.