Apple has acknowledged that they are investigating the security hole in iOS4 that renders the operating system susceptible to jailbreaking through visiting a third party website.
The jailbreak for the iPhone 4 software was released at the weekend and allows users to simply visit a website(www.jailbreakme.com) to jailbreak their device using the Safari browser on their iPhone 4. While the website method is ingenious, and does not appear to do anything except jailbreak the iPhone software, hackers could use the same hole in iOS4 and exploit it for malicious purposes.
Apple is known to strongly disapprove of jailbreaking and, additionally, is generally very quick to respond to potential security threats. The company is expected to release a fix at some point in the near future. Whether this will be tacked on to the iOS4.1 software update that was recently seeded to developers remains to be seen.