OWASP Periodic Table of Vulnerabilities - SQL Injection
Root Cause Summary
Applications that have insufficient input validation or non-validated literal strings concatenated into a dynamic SQL statement and subsequently interpreted as code by the SQL engine
Browser / Standards Solution
Web Application Firewalls (WAFs) can help in reducing SQL Injection attacks by filtering popular and well known attack inputs. WAFs are driven by a set of predefined rules that can help mitigate SQL Injection attacks to a certain extent.
Generic Framework Solution
- Parameterized Queries - Use parameterized queries to execute any SQL commands
- Input Validation - Validate all inputs that are passed to the SQL statement for accuracy of datatypes, boundary limits and accepted character set
- Escape Sequences - In cases where it is not possible to use parametric queries (like legacy code), ensure that the SQL engine sensitive characters are escaped appropriately. [ To provide a separate link for this ]
Custom Framework Solution
Custom Code Solution
- When building custom solutions, make sure that SQL queries are constructed dynamically with table names and views after thorough and proper validation of the schema and the table/view.
- As a precautionary measure, ensure that the tables have appropriate access control through policies
- Whenever possible, when building custom solutions, use the underlying databases prepared queries library.
- Stored procedures must not contain string-concatenated SQL queries, either.