Language: Java
Label: vulnerable
CWE: CWE-502 \u2014 Deserialization of Untrusted Data
The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid.

Code:
	public void writeNBTTagCompound(NBTTagCompound tag) throws IOException {
		if (tag == null) {
			writeByte(0);
		} else {
			writeByte(1);
			CompressedStreamTools.write(tag, new ByteBufOutputStream(localBuffer));
		}
	}