OWASP Periodic Table of Vulnerabilities - SQL Injection

SQL Injection

Root Cause Summary

Applications that have insufficient input validations or non-validated literal strings concatenated into a dynamic SQL Statement and subsequently interpreted as code by the SQL Engine

Browser / Standards Solution

None

Perimeter 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 Inection attacks to a certain extent.

Complexity: High
Impact: High

Generic Framework Solution

• Parametric Queries - Use parametric 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 characterset
• 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 seperate link for this ]

Complexity: Low
Impact: High

Custom Framework Solution

Provide a common configuration functionality available to any feature/function. Configuration settings should allow multiple per-user rate limits as well as global rate limits to prevent denial of service.

Complexity: Low
Impact: High

Custom Code Solution

• When building custom solutions, make sure that SQL queries are not constructed dynamically with the table names and views. If that is unavoidable, validate the schema and the table/view names before constructing the SQL query.
• As a precuationay measure, ensure that the tables have appropriate access control through policies
• Whenever possible, when building custom solutions, use the underlying databases prepared queries library.

Complexity: High
Impact: High

Discussion / Controversy

Generic framework solution requires too much overhead to track request limits. Request rate limiting should be done in perimeter, not framework. Should combine with Denial of Service (Application-Based)? Custom Code solution is the same as Custom Framework Solution; Custom Code solution should be pushed into framework.

References

Insufficient Anti-automation (WASC TC)
Brute Force (WASC TC)
Testing for Brute Force (OWASP Testing Guide)