A vulnerability has been identified in SCALANCE X200-4P IRT (All versions < V5.5.2), SCALANCE X201-3P IRT (All versions < V5.5.2), SCALANCE X201-3P IRT PRO (All versions < V5.5.2), SCALANCE X202-2IRT (All versions < V5.5.2), SCALANCE X202-2IRT (All versions < V5.5.2), SCALANCE X202-2P IRT (All versions < V5.5.2), SCALANCE X202-2P IRT PRO (All versions < V5.5.2), SCALANCE X204-2 (All versions < V5.2.6), SCALANCE X204-2FM (All versions < V5.2.6), SCALANCE X204-2LD (All versions < V5.2.6), SCALANCE X204-2LD TS (All versions < V5.2.6), SCALANCE X204-2TS (All versions < V5.2.6), SCALANCE X204IRT (All versions < V5.5.2), SCALANCE X204IRT (All versions < V5.5.2), SCALANCE X204IRT PRO (All versions < V5.5.2), SCALANCE X206-1 (All versions < V5.2.6), SCALANCE X206-1LD (All versions < V5.2.6), SCALANCE X208 (All versions < V5.2.6), SCALANCE X208PRO (All versions < V5.2.6), SCALANCE X212-2 (All versions < V5.2.6), SCALANCE X212-2LD (All versions < V5.2.6), SCALANCE X216 (All versions < V5.2.6), SCALANCE X224 (All versions < V5.2.6), SCALANCE XF201-3P IRT (All versions < V5.5.2), SCALANCE XF202-2P IRT (All versions < V5.5.2), SCALANCE XF204 (All versions < V5.2.6), SCALANCE XF204-2 (All versions < V5.2.6), SCALANCE XF204-2BA IRT (All versions < V5.5.2), SCALANCE XF204IRT (All versions < V5.5.2), SCALANCE XF206-1 (All versions < V5.2.6), SCALANCE XF208 (All versions < V5.2.6). Affected devices do not properly validate the GET parameter XNo of incoming HTTP requests. This could allow an unauthenticated remote attacker to crash affected devices.