Sql Injection Blind in Actix (Rust)

SQL Injection Blind in an Actix web service written in Rust typically arises when dynamic SQL is constructed by concatenating user-controlled input into query strings. Even though Rust’s type system and safety features reduce many classes of memory-safety bugs, they do not prevent logical flaws such as building non-parameterized queries. In Actix handlers, this often occurs when developers use raw SQL with libraries like sqlx or diesel but pass request data directly into query fragments instead of using bound parameters.

For example, consider an endpoint that filters users by a query parameter username. If the handler builds SQL via string formatting, an attacker can supply a payload such as ' OR 1=1 -- to change the query logic. In a blind SQL Injection scenario, the attacker cannot see direct output or errors; they infer behavior using time delays or boolean differences in response. Actix routes that perform unchecked string concatenation therefore expose the unauthenticated attack surface that middleBrick scans, testing inputs across multiple SQLi techniques without requiring authentication.

Because Actix is asynchronous and often uses connection pools with sqlx::PgPool (PostgreSQL) or similar, the impact can include unauthorized data access or enumeration. The 12 parallel security checks in a middleBrick scan include Input Validation and Authentication checks; for SQLi, this means probing endpoints with tautologies, UNION-based techniques, and time-based blind payloads to detect whether user input is reflected in database behavior. A vulnerable Actix endpoint will show findings such as ‘Potential SQL Injection Blind’ with severity high, tied to specific parameters and suggested remediation to use parameterized queries.

Remediation centers on using parameterized queries with bound values, ensuring user input is never concatenated into SQL strings. With sqlx, use query_as or query with bind placeholders. With diesel, rely on its query DSL which generates parameterized SQL by default. Below are concrete Actix examples demonstrating safe patterns.

Example: Safe sqlx usage in an Actix handler

use actix_web::{web, HttpResponse, Result};
use sqlx::PgPool;

#[derive(serde::Deserialize)]
struct UserQuery {
    username: String,
}

async fn get_user_handler(
    pool: web::Data,
    query: web::Query,
) -> Result<HttpResponse> {
    let user = sqlx::query_as!(User, r#"
        SELECT id, username, email
        FROM users
        WHERE username = $1
    "#)
    .bind(&query.username)
    .fetch_optional(pool.as_ref())
    .await
    .map_err(|e| actix_web::error::ErrorInternalServerError(e))?;

    match user {
        Some(u) => Ok(HttpResponse::Ok().json(u)),
        None => Ok(HttpResponse::NotFound().body("not found")),
    }
}

Key points: the SQL string uses $1 as a positional placeholder, and .bind(&query.username) ensures the value is sent separately from the query structure. This prevents an attacker’s input from altering query intent, effectively mitigating blind SQL Injection.

Example: Safe diesel usage in an Actix handler

use actix_web::{web, HttpResponse, Result};
use diesel::prelude::*;
use crate::schema::users::dsl::*;

#[derive(Queryable, serde::Serialize)]
struct User {
    id: i32,
    username: String,
    email: String,
}

async fn safe_user_lookup(
    pool: web::Data>>,
    web::Query(params): web::Query<UserQuery>,
) -> Result<HttpResponse> {
    use crate::schema::users::filter;
    let user = users
        .filter(username.eq(params.username))
        .first<User>(&mut *pool)
        .map_err(|e| actix_web::error::ErrorInternalServerError(e))?;

    Ok(HttpResponse::Ok().json(user))
}

With diesel, the query DSL methods like filter produce parameterized SQL; avoid sql_query with raw strings unless using bound parameters via .bind(). This keeps the Actix route resilient against blind SQL Injection patterns that middleBrick’s Input Validation and Authentication checks would otherwise flag.