What it is
Injection vulnerabilities arise when untrusted input is passed to an interpreter as part of a command or query, allowing attackers to alter the intended execution. SQL injection targets databases by embedding malicious statements into application inputs to exfiltrate data or modify schemas. Command injection affects operating system calls, while LDAP, NoSQL, and template injection impact other data stores and renderers. These flaws exist when applications concatenate user input with executable code without proper context-aware validation or parameterization. Attackers enumerate inputs via web forms, APIs, HTTP headers, or serialized objects, crafting payloads that exploit parsing nuances. Injection issues persist despite mature guidance because legacy code, rapid development cycles, and complex query builders create blind spots. Framework features like Object-Relational Mappers can reduce risk, but misconfiguration and raw queries often reintroduce vulnerabilities. Effective defense requires treating every input as hostile and using security libraries built to enforce consistent, robust handling.
Why it matters
Injection attacks have enabled some of the largest data breaches on record, granting attackers direct access to sensitive records, administrative credentials, and system-level control. Regulatory penalties, customer churn, and incident response costs skyrocket when databases are compromised.
How to reduce risk
- Use prepared statements or parameterized queries for all database interactions, avoiding dynamic SQL composition.
- Implement rigorous input validation and encoding that aligns with the downstream interpreter (SQL, shell, LDAP).
- Enforce least privilege on database accounts so even successful injection has minimal impact.
- Adopt automated scanning and secure code reviews focused on spotting dangerous concatenation patterns.