Mozilla Firefox 3.0.13 and earlier, 3.5, 3.6 a1 pre, and 3.7 a1 pre; SeaMonkey 1.1.17; and Mozilla 1.7.x and earlier do not properly block data: URIs in Refresh headers in HTTP responses, which allows remote attackers to conduct cross-site scripting (XSS) attacks via vectors related to (1) injecting a Refresh header that contains JavaScript sequences in a data:text/html URI or (2) entering a data:text/html URI with JavaScript sequences when specifying the content of a Refresh header. NOTE: in some product versions, the JavaScript executes outside of the context of the HTTP site.

Visual truncation vulnerability in Mozilla 1.7.12 allows remote attackers to spoof the address bar and possibly conduct phishing attacks via a long hostname, which is truncated after a certain number of characters, as demonstrated by a phishing attack using HTTP Basic Authentication.

Cross-site scripting (XSS) vulnerability in Mozilla 1.7.12 and possibly earlier, Mozilla Firefox 1.0.7 and possibly earlier, and Netscape 8.1 and possibly earlier, allows remote attackers to inject arbitrary web script or HTML via the -moz-binding (Cascading Style Sheets) CSS property, which does not require that the style sheet have the same origin as the web page, as demonstrated by the compromise of a large number of LiveJournal accounts.

Firefox and Mozilla can associate a cookie with multiple domains when the DNS resolver has a non-root domain in its search list, which allows remote attackers to trick a user into accepting a cookie for a hostname formed via search-list expansion of the hostname entered by the user, or steal a cookie for an expanded hostname, as demonstrated by an attacker who operates an ap1.com Internet web site to steal cookies associated with an ap1.com.example.com intranet web site.