A vulnerability has been identified in SIMATIC PCS neo V4.0 (All versions), SIMATIC PCS neo V4.1 (All versions < V4.1 Update 2), SIMATIC PCS neo V5.0 (All versions < V5.0 Update 1), SIMOCODE ES V19 (All versions < V19 Update 1), SIRIUS Safety ES V19 (TIA Portal) (All versions < V19 Update 1), SIRIUS Soft Starter ES V19 (TIA Portal) (All versions < V19 Update 1), TIA Administrator (All versions < V3.0.4). Affected products do not correctly invalidate user sessions upon user logout. This could allow a remote unauthenticated attacker, who has obtained the session token by other means, to re-use a legitimate user's session even after logout.