A vulnerability has been identified in SIMATIC WinCC OA V3.15 (All versions < V3.15 P038), SIMATIC WinCC OA V3.16 (All versions < V3.16 P035), SIMATIC WinCC OA V3.17 (All versions < V3.17 P024), SIMATIC WinCC OA V3.18 (All versions < V3.18 P014). The affected component allows to inject custom arguments to the Ultralight Client backend application under certain circumstances. This could allow an authenticated remote attacker to inject arbitrary parameters when starting the client via the web interface (e.g., open attacker chosen panels with the attacker's credentials or start a Ctrl script).