How do I avoid SQL injection vulnerabilities when using raw DB expressions in Eloquent

Use Parameterized Queries and Bindings

- Laravel’s Eloquent ORM and Query Builder automatically protect against SQL injection by using parameterized queries and binding user inputs as parameters rather than concatenating them directly into SQL strings. For example:

php
User::where('email', $email)->get();

This generates a query where the email is safely bound as a parameter, preventing injection[5][7].

- When using raw expressions like `whereRaw()`, `selectRaw()`, or `orderByRaw()`, never concatenate user input directly into the raw SQL string. Instead, use parameter binding provided by Laravel:

php
DB::table('posts')
  ->whereRaw('id = ?', [$id])
  ->get();

This ensures `$id` is treated as data, not executable SQL[1][8].

Avoid Direct Concatenation of User Input in Raw Queries

- Directly appending user input into raw SQL strings, such as:

php
->whereRaw('id = ' . $id)

is vulnerable to SQL injection because malicious input can alter the query logic[1].

- Always use placeholders (`?`) and pass user input as bindings to prevent attackers from injecting SQL code[1][8].

Validate and Sanitize User Inputs

- Before using any user input in queries (even with bindings), validate and sanitize inputs according to expected formats and rules. This reduces the risk of malicious data being processed[2][7].

Limit Database Permissions

- Restrict the database user permissions to only what is necessary (principle of least privilege). For example, if the app only needs read access, do not grant write or admin permissions. This limits potential damage even if injection occurs[2].

Prefer Eloquent and Query Builder Over Raw Queries

- Use Eloquent ORM or Laravel’s Query Builder for most database interactions as they handle parameter binding automatically.

- Resort to raw expressions only when absolutely necessary, and always with parameter binding[4].

Example of Safe Raw Query Usage

php
DB::select('SELECT * FROM users WHERE email = ?', [$email]);

This is safe because it uses parameterized queries, even though it’s a raw SQL query[6].

By adhering to these guidelines-using parameter binding with raw expressions, validating inputs, limiting permissions, and preferring Eloquent/Query Builder-you can effectively avoid SQL injection vulnerabilities when using raw DB expressions in Laravel Eloquent.

Citations:
[1] https://www.stackhawk.com/blog/sql-injection-prevention-laravel/
[2] https://escape.tech/blog/laravel-sql-injection-guide/
[3] https://zerothreat.ai/blog/how-to-prevent-sql-injection-attacks-in-laravel
[4] https://brightsec.com/blog/sql-injection-in-laravel-everything-you-need-to-know/
[5] https://cheatsheetseries.owasp.org/cheatsheets/Laravel_Cheat_Sheet.html
[6] https://stackoverflow.com/questions/59229544/insert-using-a-raw-sql-query-to-avoid-sql-injection
[7] https://acquaintsoft.com/answers/what-is-sql-injection-protection-in-laravel
[8] https://stackoverflow.com/questions/60332447/how-can-i-secure-this-sql-query-from-sql-injection-in-laravel