The SCALANCE W700 devices are affected by Wi-Fi encryption bypass vulnerabilities (“Framing Frames”) that could allow an attacker to disclose sensitive information, to steal the victims session or to execute denial-of-service attacks.
Siemens recommends countermeasures for products where fixes are not, or not yet available.

https://cert-portal.siemens.com/productcert/html/ssa-457702.html