A vulnerability has been identified in SIMATIC CP 1604 (All versions), SIMATIC CP 1616 (All versions), SIMATIC CP 1623 (All versions), SIMATIC CP 1626 (All versions), SIMATIC CP 1628 (All versions). The kernel memory of affected devices is exposed to user-mode via direct memory access (DMA) which could allow a local attacker with administrative privileges to execute arbitrary code on the host system without any restrictions.
https://cert-portal.siemens.com/productcert/pdf/ssa-784849.pdf