A vulnerability has been identified in SIMATIC HMI Comfort Panels 4" - 22" (All versions < V15.1 Update 1), SIMATIC HMI Comfort Outdoor Panels 7" & 15" (All versions < V15.1 Update 1), SIMATIC HMI KTP Mobile Panels KTP400F, KTP700, KTP700F, KTP900 und KTP900F (All versions < V15.1 Update 1), SIMATIC WinCC Runtime Advanced (All versions < V15.1 Update 1), SIMATIC WinCC Runtime Professional (All versions < V15.1 Update 1), SIMATIC WinCC (TIA Portal) (All versions < V15.1 Update 1), SIMATIC HMI Classic Devices (TP/MP/OP/MP Mobile Panel) (All versions). The integrated web server could allow Cross-Site Scripting (XSS) attacks if an attacker is able to modify particular parts of the device configuration via SNMP. The security vulnerability could be exploited by an attacker with network access to the affected system. Successful exploitation requires system privileges and user interaction. An attacker could use the vulnerability to compromise confidentiality and the integrity of the affected system. At the stage of publishing this security advisory no public exploitation is known.