This indicates a possible exploit of a buffer overflow attack against a Web browser.
The Mozilla/Netscape/Firefox web browsers are vulnerable to a buffer overflow attack due to a lack of input validation when handling a malformed URI. This can lead to the execution of arbitrary code or a denial of service condition.
Netscape Netscape 7.2
Netscape Browser 220.127.116.11
Mozilla Thunderbird 1.0.6
Mozilla Firefox 1.5 beta 1 and earlier versions.
Mozilla Browser 1.7.11 and earlier versions.
Denial of Service.
Apply the appropriate patch from the vendor or upgrade to a non-vulnerable version.