Yes. This is a massive security hole that Apple is sure to fix as soon as possible. I don't know if this jailbreak does it, but the old (iPhoneOS 1.1.1) jailbreakme.com not only exploited the TIFF vulnerability, but also patched it so it couldn't be used by anyone else. It would have been nice if they just offered an option to patch without jailbreaking though.
Fortunately, it's not just a copypasta Javascript exploit or anything of the sort - you have to actually know what you're doing in detail to modify this exploit to do what you want.
Fortunately, it's not just a copypasta Javascript exploit or anything of the sort - you have to actually know what you're doing in detail to modify this exploit to do what you want.