MCPE-185692Chest + Redstone Engine + Block Breaking can crash any server/World on all Bedrock Versions
*Apologies in advance for writing about this issue in letter format, but it is of the utmost importance that reviewers understand the severity of this issue and how I discovered it.
Hello, my name is CaRto0NiSt.
I build large amounts of Redstone daily, ranging from computers to doors to Flying Machines.
Over the course of the past 2 weeks, for the first time since 2011, I have not been able to create any flying machines without incurring an instantaneous crash of my phone. At first I was under the impression that the bug only impacted myself and my LAN worlds, but after noticing that all my friends and their worlds crashed whenever I built simple Redstone Engines within them, I knew that the issue was much more serious.
I am 100% certain that this bug may allow individuals with malicious intent to crash any server or LAN world in which they have access to building permissions and basic Redstone and Flying Machine Materials (Slime-Stone)
This bug not only affects the average player who is building a flying machine for peaceful purposes, but gives bad actors a tool that is easily obtainable; one that will likely allow them to cause serious damage. That is why I have opted to keep this PRIVATE.
I implore those reading to do everything in their power to ensure that this fatal bug is patched before those with evil intentions discover this bug and exploit it.
Below I have listed all the information I know of the bug and how to reproduce it effectively:
- The bug is triggered whenever a Redstone Flying Machine is activated and begins moving, and then is broken or stopped by a player as it moves, however, this is more random and happens when a machine is stopped and started rapidly in quick succession.
- The bug can be forced to activate quickly if the engine is triggered through a redstone pulse from a trapped chest being rapidly triggered and stopped.
- Placing a trapped chest on the engine, and rapidly opening it as the machine moves is a fast way to trigger the crash bug, regardless of whether or not the trapped chest is powering the engine.
- The fastest way to trigger the bug is to build the community standard basic Redstone engine, which I will attach to this report, and then place a trapped chest on top of the slime, on a corner of the rectangular engine (Not adjacent to the pistons) Use flint and steel and tap it on the "Face" of one of the observers to get the engine to start moving. Once it is moving, rapidly spam-click (open) the chest menu. As the machine moves, it will kick you out of the chest's menu, like all Tile Blocks when pushed by a Piston (This is Bedrock Edition Exclusive and to be expected) Continue spam-clicking into the chest menu about 5-10 times, and then attempt to mine the machine as it is moving. This should trigger an immediate crash.
- Upon logging back into the game, the machine will have disappeared (This is a side-effect of the bug, not the actual bug) This is just a result of the machine becoming an entity, the game crashing, which interrupts the auto-save and the machine in it's entity form disappears upon logging back in. This is normal in ANY crash scenario, not just this bug.
(Video not owned by me) BELOW IS THE LINK TO A SIMPLE ENGINE/FLYING MACHINE:
*Note: You must use the Bedrock Edition version of the machine contained in the video. You must also add a trapped chest to one of the corners (On top of a slime block, just not adjacent to a piston) This will be shown in the second attached image.
Below is what the machine should look like when finished. It is the standard community flying machine with a trapped chest installed on a corner. This is the machine that should be used to trigger the bug. I decided to build the testing machine like this to make it as simple as possible for those who do not use Redstone.
