have wanted that Firefox combined with Internet Explorer on the same desktop opens up a highly critical zero-day vulnerability.
Both Symantec and Secunia have reported the problem but neither is quite sure which browser is responsible.
According to Cnet, the problem is caused when browsing a malicious site while using IE and it registers a "firefoxurl://" URI (uniform resource identifier) handler, which allows the browser to interact with specific resources on the Web. As a result, users may find their systems remotely compromised.
Symantec's Security Response Center said that the two browsers were not playing well together and leading to a security issue. They are secure as stand-alone browsers but not together.
System administrators could unregister, or remove, the "Firefox URL" URI handler, as well as change the way Firefox accepts the chrome input.