SQL injection and XSS need different defensive controls
Prevent injection at database and browser boundaries instead of relying on a universal input filter.
Contents of this article
Distinguish the execution context
OWASP A05:2025 covers injection. SQL injection crosses a query boundary, while XSS crosses a browser execution boundary. Database parameterization and contextual output encoding address different problems.
Separate query structure from values
Use parameterized queries and map dynamic identifiers or sort choices to approved options. Limit database privileges and audit exports or batch jobs that bypass shared access layers. An ORM does not make every raw query safe.
Encode at the rendering boundary
Treat text, attributes, URLs and script contexts separately. Sanitize permitted rich text and review direct HTML insertion. Content Security Policy is supplementary; keyword removal is not a complete encoding strategy.
Test realistic content and trust boundaries
Test search, comments, names, exports and administrative views in an owned test environment. Check both trust boundaries and legitimate rich content. Use supported WAF controls alongside fixes to query and rendering logic.
References
OWASP SQL injection prevention