Buffer overflow in the International Domain Name (IDN) support in Mozilla Firefox 1.0.6 and earlier and Netscape 8.0.3.3 and 7.2 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a hostname with all \soft\ hyphens (character 0xAD) which is not properly handled by the NormalizeIDN call in nsStandardURL::BuildNormalizedSpec.