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 writeByteArray(byte[] arr) throws IOException {
		if (arr == null) {
			writeInt(-1);
		} else {
			writeInt(arr.length);
			writeBytes(arr);
		}
	}