3776270 - ESI - WS-Security UsernameToken authentication fails with "DELAY_LOGON" when user type is System

When calling a SOAP web service using WS-Security Message Level Authentication with UsernameToken (User ID/Password sent in the SOAP header via <wsse:Security>), the request fails with:

• HTTP 500 – Internal Server Error
• SRT_UTIL / Error Log entry: 
  DELAY_LOGON (user) — Authentication failed (Method wsse:UsernameToken, SRTUTIL Transaction Id xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx) MODULE: AUTHENTICATE

The authentication error is logged for the user DELAY_LOGON even though the correct User ID and password are being provided in the SOAP header.

The credentials are valid (they can be used to log on successfully via other channels, e.g., SU01 test, basic authentication pop-up, SAP GUI logon).

• SAP NetWeaver
• SAP Web Application Server for SAP S/4 HANA
• ABAP PLATFORM - Application Server ABAP
• SAP S/4HANA (on-premise) 

 WS-Security, WSS, UsernameToken, Message Authentication, DELAY_LOGON, WSS038, SOAMANAGER, SOAP, HTTP 500, Authentication failed, user type System, user type Service, 401, Unauthorized , KBA , BC-ESI-WS-ABA-CFG , WebServices ABAP Configuration , BC-ESI-WS-ABA , Web Service and SOAP - ABAP , Problem