Exploit For Crashing Minecraft Servers Made Public

An anonymous reader writes "After nearly two years of waiting for Mojang to fix a security vulnerability that can be used to crash Minecraft servers, programmer Ammar Askar has released a proof of concept exploit for the flaw in the hopes that this will force them to do something about it. "Mojang is no longer a small indie company making a little indie game, their software is used by thousands of servers, hundreds of thousands people play on servers running their software at any given time. They have a responsibility to fix and properly work out problems like this," he noted." Here is Askar's own post on the exploit, and his frustration with the response he's gotten to disclosing it to the developers.

Comments

I am completely unsurprised.

[MostAwesomeDude]

I spent four damn years trying to have a dialog with Mojang and Bukkit about how to write good code and have a community that wants good code. The MC community literally does not want anybody participating if they have any sense of QA or planning for the future.

Remember, these are people that wrote their own cryptographic transport *three times* and called it good after nobody could post an exploit for it within a week. MC is not even willing to use standard things like TLS.

Re:I like it...

[Rei]

I once coded for a game, Eternal Lands, where I discovered a major security bug. The game had a feature where if a person said a URL, it would turn into a clickable link. This was opened via a popen call. No input sanitization. Aka, vulnerable to injection. A person who simply speaks a malicious URL and makes it look like something interesting to click (hiding the insertion command in the path) could run it on anyone's computer who clicks to open the link.

Big problem. Simple fix. But try as I might, I couldn't get them to let me fix it. They were fine with me writing a whole new special effects graphics system for them, but one simple input sanitization, noooo, the popen works, let's not mess with it and possibly "introduce a bug"! Eventually it took me writing a sample command on the forum that would make a file in the user's home directory (which anyone who knows anything about unix commands could make far more malicious) by clicking on the URL. Suddenly they let me patch the system immediately (and deleted the forum thread... I don't blame them).

I didn't want to have to resort to that. But I didn't want a potentially dangerous exploit sitting in the system.

I never got approval to fix all of the other potential exploits in their system. Their networking protocol was terrible. I only ever saw the client code, but there was literally zero authentication that the server was who they said they were and that packets weren't malformed. Their entire security model was "let's initiate a TCP connection to a hard-coded IP and unconditionally trust everything that we receive". I can't imagine what their server code is like. But they wouldn't even let me add in trivial bounds checking to make sure that the packets weren't oversized - the most minimal of sanity checking.

The fear of changes breaking stuff often leads developers to neglect security. Changes to improve gameplay or graphics? Of course, our users will love it! Changes to the protocol? Nonono, the protocol is working, why risk breaking it?

The short of it? Don't have too much faith that that MMORPG you're playing isn't hackable in a way that could be nasty to your system.