This indicates a possible exploit of an HTML Injection vulnerability in Mozilla or Firefox Browser.
Mozilla and Firefox browsers are prone to a programming error that makes them vulnerable to HTML Injection attacks. This vulnerability can be used to mount further attacks against server or proxy flaws.
Mozilla Thunderbird 1.0.6 and earlier versions. Mozilla Firefox 1.0.6 and earlier versions.
Can be used to leverage attacks against server processes.
Apply appropriate patch from the vendor or Upgrade to a non-vulnerable version if available.