CVE 2013-1678
The _cairo_xlib_surface_add_glyph function in Mozilla Firefox before 21.0, Firefox ESR 17.x before 17.0.6, Thunderbird before 17.0.6, and Thunderbird ESR 17.x before 17.0.6 allows remote attackers to execute arbitrary code or cause a denial of service (invalid write operation) via unspecified vectors.