The bdfReadCharacters function in bitmap/bdfread.c in X.Org libXfont before 1.4.9 and 1.5.x before 1.5.1 does not properly perform type conversion for metrics values, which allows remote authenticated users to cause a denial of service (out-of-bounds memory access) and possibly execute arbitrary code via a crafted BDF font file. http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2015-1804