Mozilla based browsers, including Firefox before 1.5.0.10 and 2.x before 2.0.0.2, and SeaMonkey before 1.0.8, allow remote attackers to bypass the same origin policy, steal cookies, and conduct other attacks by writing a URI with a null byte to the hostname (location.hostname) DOM property, due to interactions with DNS resolver code.
Exploitability
AV:NAC:LAu:NImpact
C:PI:PA:P7.5/AV:N/AC:L/Au:N/C:P/I:P/A:P