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 writeItemIdentifierStack(ItemIdentifierStack stack) throws IOException {
		if (stack == null) {
			writeInt(-1);
		} else {
			writeInt(stack.getStackSize());
			writeItemIdentifier(stack.getItem());
		}
	}