The 5 Biggest Traps When Writing Your Own SQL Injection Filter

SQL injection is one of those vulnerabilities every developer thinks they understand — until their handcrafted “secure” filter gets bypassed by a payload they never anticipated. The pattern repeats constantly: A project launches fast. Someone adds a few blacklist rules. A regex grows into a monster. Edge cases accumulate. Attackers eventually walk straight through it. Despite two decades of awareness, SQL injection remains part of the OWASP Top 10 because many defenses are still fundamentally fl