Subject: SAP-ABAP-Crimes in SAP Field
Internal tables are fundamental data structures in ABAP programming, widely used to manipulate and store temporary data sets during program execution. While essential for performance and flexibility, improper handling of internal tables can introduce security risks such as unauthorized data exposure, data corruption, or even system manipulation—issues that can contribute to SAP-ABAP crimes when exploited maliciously.
This article outlines best practices for securely handling internal tables in ABAP to protect sensitive data and maintain system integrity.
Declare internal tables with the narrowest possible scope (local to the procedure or method) to reduce the risk of unintended access or modification.
DATA: lt_sensitive_data TYPE TABLE OF z_sensitive_structure WITH EMPTY KEY.
Before inserting data into internal tables, perform strict validation, especially for data coming from user inputs, interfaces, or external systems.
IF lv_input IS NOT INITIAL AND lv_input CP '[A-Za-z0-9]+'.
APPEND lv_input TO lt_data.
ELSE.
MESSAGE 'Invalid input data' TYPE 'E'.
ENDIF.
Before processing or displaying data stored in internal tables, use AUTHORITY-CHECK to ensure the current user has rights to access the data.
LOOP AT lt_sensitive_data INTO DATA(ls_data).
AUTHORITY-CHECK OBJECT 'Z_SENSITIVE_ACCESS'
ID 'MANDT' FIELD sy-mandt
ID 'DATAID' FIELD ls_data-id.
IF sy-subrc <> 0.
CONTINUE.
ENDIF.
" Process ls_data safely
ENDLOOP.
Clear internal tables holding sensitive data as soon as their purpose is complete to minimize risk.
CLEAR lt_sensitive_data.
FREE lt_sensitive_data.
Never directly concatenate external input into dynamic commands or queries involving internal tables without proper escaping and validation.
Use appropriate table types (sorted, hashed) and size checks to prevent uncontrolled growth.
DATA: lt_customers TYPE TABLE OF z_customer_data WITH EMPTY KEY.
" Validate and insert customer data
LOOP AT it_input_customers INTO DATA(ls_customer).
IF ls_customer-customer_id IS NOT INITIAL AND ls_customer-name IS NOT INITIAL.
AUTHORITY-CHECK OBJECT 'Z_CUSTOMER_ACCESS'
ID 'CUSTOMER' FIELD ls_customer-customer_id.
IF sy-subrc = 0.
APPEND ls_customer TO lt_customers.
ELSE.
" Log unauthorized attempt
CALL FUNCTION 'Z_LOG_UNAUTHORIZED_ACCESS'
EXPORTING
user = sy-uname
data = ls_customer-customer_id.
ENDIF.
ELSE.
MESSAGE 'Invalid customer data' TYPE 'E'.
ENDIF.
ENDLOOP.
Internal tables are indispensable in ABAP, but careless handling can lead to security vulnerabilities and abuse, potentially facilitating SAP-ABAP crimes. By applying validation, authorization checks, memory management, and secure coding principles when working with internal tables, developers can ensure data integrity, confidentiality, and system robustness.