Dynamic SQL statements in ABAP allow the construction and execution of database queries at runtime, offering flexibility but also posing significant security risks. In SAP systems, improper use of dynamic SQL can open doors for SAP-related crimes such as SQL injection attacks, data manipulation, and unauthorized access. For ABAP developers and security professionals, avoiding or carefully controlling dynamic SQL usage is essential to maintain the integrity and security of SAP applications.
Dynamic SQL refers to SQL statements that are constructed as strings during program execution, rather than being statically coded. For example:
DATA lv_sql TYPE string.
lv_sql = |SELECT * FROM mara WHERE matnr = '{ lv_matnr }'|.
EXEC SQL.
EXECUTE IMMEDIATE :lv_sql
ENDEXEC.
Unlike Open SQL, which is embedded directly in ABAP with compile-time checks, dynamic SQL is parsed and executed at runtime, increasing the risk of runtime errors and security vulnerabilities.
Dynamic SQL constructed from untrusted input can allow attackers to inject malicious code, potentially leading to unauthorized data access, modification, or deletion.
Errors in dynamic SQL are detected only at runtime, making debugging harder and increasing the risk of security flaws slipping into production.
Dynamic SQL complicates code readability and audit trails, making security reviews and compliance checks challenging.
Dynamic SQL may prevent the database from optimizing query execution plans effectively, leading to suboptimal performance.
Open SQL is integrated with ABAP, provides database independence, supports host variables, and includes built-in safeguards against injection attacks.
Example:
SELECT * FROM mara INTO TABLE @DATA(lt_mara) WHERE matnr = @lv_matnr.
Native SQL offers database-specific features but should be used cautiously with parameter binding to prevent injection.
Never construct SQL queries by concatenating strings from user input. Instead, use parameterized queries and host variables.
If dynamic SQL cannot be avoided, ensure all input parameters are validated against allowed patterns and sanitized.
Regularly audit code to detect and refactor dynamic SQL statements, using tools like SAP Code Vulnerability Analyzer.
DATA lv_matnr TYPE string.
lv_matnr = user_input.
DATA lv_sql TYPE string.
lv_sql = |SELECT * FROM mara WHERE matnr = '{ lv_matnr }'|.
EXEC SQL.
EXECUTE IMMEDIATE :lv_sql
ENDEXEC.
If user_input contains malicious SQL, it can manipulate or damage the database.
When dynamic SQL is indispensable:
cl_sql_statement and cl_sql_prepared_statement classes to prepare and execute statements safely.Avoiding dynamic SQL statements in ABAP is a vital security practice to protect SAP systems from SQL injection and related crimes. Leveraging Open SQL, enforcing strict input validation, and adopting safe coding practices safeguard SAP data integrity and system stability. For SAP organizations aiming to enhance their security posture, minimizing dynamic SQL usage is a foundational step toward reducing vulnerabilities and thwarting SAP-related cyber threats.