The WinCC server in Siemens SIMATIC WinCC 7.0 through SP3, 7.2 before Update 9, and 7.3 before Update 2; SIMATIC PCS 7 7.1 through SP4, 8.0 through SP2, and 8.1; and TIA Portal 13 before Update 6 allows remote attackers to read arbitrary files via crafted packets.