The RFTools Builder block is ignoring all metadata and allowing the transmutation, and in some cases duplication of blocks. A player on our server (AlienMC) reported this as of this morning.

Pack: AlienMC 2.0.1 (PurpleAlienPenguins Private Pack Code)
RF Tools Version: 3.11

Method:

Create a Space Chamber card containing the blocks you wish to dupe - in this example Enderium Blocks and Unstable Ingot Blocks were duped.

For materials, supply the builder with a block with the same id, but different metadata. (For example, Enderium blocks are 432:12, I can use copper blocks, 432, for transmutation. Similarly, I can use sandly glass, 1471:9 to make 1471:5, unstable ingot blocks).

Apply a redstone signal and power, and you're making enderium out of copper, and unstable ingot blocks out of sandy glass. Gamebreaking.

@McJty: I've looked through the documentation for https://github.com/McJty/RFTools/wiki/Builder-Configuration, and I understand what you mean. But it seems like there should maybe be verification of the unlocalized block name for the source materials, if that is possible?

I get that the ability to copy the metadata, and accept blocks of differing metadata is a great thing for the builder being able to handle rotatables, but the number of exploits this currently allows is insane, it can change any thermal expansion machine into any other thermal expansion machine (which is being allowed even though we have an emtpy builder config and whitelist mode on), transmute material blocks (an exploit which is not solved by using tile entity whitelist mode) and more, just with mere minutes of testing.

So many mods use a single itemid for multiple blocks of completely different purpose nowadays. Maybe this problem will be solved by a complete move to unlocalized names (I am not a modder, and only mildly versed in how this change will affect the itemid system), but for now it remains an exploit which would require a significant amount of blacklisting to fix for each pack RFTools is in.

It is easy to fix this in the config. The builder can be configured to indicate how it should copy metadata for a given block. I don't have time to clarify this right now though. Will check on this tomorrow.

Ok, I can confirm the bug. Seems to be only a problem in Build mode. In move mode it is ok. I'll see on fixing this

Fixed for 3.33