SSA-111512: Client-side Authentication in SIMATIC WinCC OA

SIMATIC WinCC OA implements client-side only authentication, when neither server-side authentication (SSA) nor Kerberos authentication is enabled. In this configuration, attackers could impersonate other users or exploit the client-server protocol without being authenticated.

Siemens recommends to enable server-side authentication (SSA) or Kerberos authentication for all WinCC OA projects, as documented in the WinCC OA Security Guideline. In SIMATIC WinCC OA server-side authentication is available since V3.15 (and offered as the default configuration since V3.17). Additional information can be found at: https://cert-portal.siemens.com/productcert/news.html?id=21.