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.

Mozilla Firefox 1.0.7 and earlier on Linux allows remote attackers to cause a denial of service (client crash) via an IFRAME element with a large value of the WIDTH attribute, which triggers a problem related to representation of floating-point numbers, leading to an infinite loop of widget resizes and a corresponding large number of function calls on the stack.

Mozilla Firefox 1.5, Netscape 8.0.4 and 7.2, and K-Meleon before 0.9.12 allows remote attackers to cause a denial of service (CPU consumption and delayed application startup) via a web site with a large title, which is recorded in history.dat but not processed efficiently during startup. NOTE: despite initial reports, the Mozilla vendor does not believe that this issue can be used to trigger a crash or buffer overflow in Firefox. Also, it has been independently reported that Netscape 8.1 does not have this issue.