Mac Rumors posted a news story that Apple is investigating the iOS vulnerability that allowing web-based jailbreak

At the time, we noted potential security implications of the method, which involves a security hole in how the mobile Safari browser included on all iOS devices handles embedded fonts. Exploiting the hole allows a remote site to gain control over a user's device. In the case of the new JailbreakMe site, the exploit is offering a convenient delivery method for a service, but others could use the same method for malicious purposes.

  Apple Investigating iOS Vulnerability Allowing Web-Based Jailbreak