Broken Access Control in Rocket

Broken Access Control in Rocket applications typically emerges through predictable patterns that exploit the framework's request handling and authorization mechanisms. The most common manifestation occurs when developers rely solely on client-side state or URL manipulation to control access to resources.

Consider a typical Rocket endpoint that serves user data:

#[get("/users/")]
fn get_user(id: i32) -> Json<User> {
    let user = db::get_user_by_id(id);
    Json(user.unwrap())
}

This endpoint exposes a critical vulnerability. An authenticated user can simply change the id parameter in the URL to access any other user's data. This is classic IDOR (Insecure Direct Object Reference) - the application trusts the client to provide valid identifiers without verifying ownership.

Another common pattern involves improper use of Rocket's request guards. Developers often create guards that check authentication but fail to verify authorization:

#[get("/admin/dashboard")] 
fn admin_dashboard(_user: AuthenticatedUser) -> Template {
    // No role check - any authenticated user can access
    let data = admin::get_dashboard_data();
    Template::render("admin", data)
}

The AuthenticatedUser guard only verifies that a user is logged in, not that they have admin privileges. This allows any authenticated user to access administrative functionality.

Property-level authorization failures are particularly insidious in Rocket. Developers might properly check that a user can view a resource but fail to verify they can modify specific properties:

#[put("/users/")]
fn update_user(id: i32, user: Json<UserUpdate>, _auth: AuthenticatedUser) -> Json<User> {
    // Only checks user can update profile, not specific fields
    let updated = db::update_user(id, user.0);
    Json(updated.unwrap())
}

This allows privilege escalation where a user can modify fields they shouldn't have access to, such as changing their role or permissions.

Rocket's async nature introduces additional complexity. Race conditions can occur when authorization checks happen before database operations complete:

#[post("/transfer///")]
async fn transfer(from: i32, to: i32, amount: f64, _auth: AuthenticatedUser) -> Json<Transaction> {
    // Authorization check happens before async operations
    if from != _auth.user_id { return Err(...); }
    
    let from_balance = db::get_balance(from).await;
    let to_balance = db::get_balance(to).await;
    
    // Between the check and the transfer, balances could change
    db::transfer_funds(from, to, amount).await?;
    
    Json(transaction)
}

The authorization check completes before the actual balances are retrieved, creating a window where the state could change and bypass the security check.

Detecting Broken Access Control in Rocket applications requires both static analysis of the codebase and dynamic testing of the running application. The patterns are often subtle and require understanding Rocket's specific request handling flow.

Static analysis should focus on these Rocket-specific patterns:

# Look for unprotected routes
rg 'fn [a-zA-Z_]+\(' --type rust | 
  rg -v 'AuthenticatedUser|AdminGuard|Admin|mod' | 
  rg 'get\(|post\(|put\(|delete\(' 

# Find IDOR patterns
rg 'users?/[0-9]+' --type rust
rg 'get_user_by_id|find_by_id' --type rust

# Check for missing authorization in guards
rg 'AuthenticatedUser' --type rust | 
  rg -v 'Admin|Role|Permission'

Dynamic testing requires systematically testing each endpoint with different user contexts. For the IDOR example above, you would:

# Test IDOR vulnerability
curl -H "Authorization: Bearer $USER1_TOKEN" \
  http://localhost:8000/users/1 | jq '.id'

curl -H "Authorization: Bearer $USER2_TOKEN" \
  http://localhost:8000/users/1 | jq '.id'

middleBrick's black-box scanning approach is particularly effective for Rocket applications because it doesn't require source code access. The scanner automatically tests for Broken Access Control patterns by:

• Testing authenticated endpoints with unauthenticated requests to verify authentication requirements
• Modifying URL parameters to test for IDOR vulnerabilities
• Testing different user roles against endpoints that should have role-based access control
• Checking for property-level authorization failures by attempting to modify restricted fields

For Rocket applications with OpenAPI specs, middleBrick can cross-reference the documented security requirements with actual runtime behavior, identifying discrepancies where the spec claims authentication is required but the endpoint is actually accessible without credentials.

The scanner's LLM/AI security checks are particularly relevant for Rocket applications using AI features, testing for prompt injection and other AI-specific vulnerabilities that could lead to access control bypasses.

Remediating Broken Access Control in Rocket requires implementing proper authorization checks at the appropriate layers. The most effective approach uses Rocket's request guard system to centralize authorization logic.

For IDOR prevention, implement ownership checks in your request guards:

struct UserOrAdmin(i32);

impl<'a, 'r> FromRequest<'a, 'r> for UserOrAdmin {
    type Error = &'static str;
    
    async fn from_request(request: &'a Request<'r>) -> Outcome<Self, Self::Error> {
        let auth = request.guard::<AuthenticatedUser>().await?;
        let id: i32 = request.get_param(0).unwrap();
        
        if auth.user_id == id || auth.is_admin() {
            return Outcome::Success(UserOrAdmin(id));
        }
        
        Outcome::Failure((Status::Forbidden, "Access denied"))
    }
}

#[get("/users/")]
fn get_user(id: i32, _auth: UserOrAdmin) -> Json<User> {
    let user = db::get_user_by_id(id).unwrap();
    Json(user)
}

This guard ensures users can only access their own data or have admin privileges. The authorization check happens before the route handler executes.

For role-based access control, create reusable guards:

struct AdminGuard;

impl<'a, 'r> FromRequest<'a, 'r> for AdminGuard {
    type Error = &'static str;
    
    async fn from_request(request: &'a Request<'r>) -> Outcome<Self, Self::Error> {
        let auth = request.guard::<AuthenticatedUser>().await?;
        
        if auth.role == "admin" {
            return Outcome::Success(AdminGuard);
        }
        
        Outcome::Failure((Status::Forbidden, "Admin access required"))
    }
}

#[get("/admin/stats")]
fn admin_stats(_guard: AdminGuard) -> Json<AdminStats> {
    let stats = admin::get_stats();
    Json(stats)
}

Property-level authorization requires checking specific field permissions:

#[derive(Deserialize)]
struct UserUpdate {
    email: Option<String>,
    role: Option<String>,
    can_publish: Option<bool>,
}

#[put("/users/")]
fn update_user(id: i32, update: Json<UserUpdate>, auth: AuthenticatedUser) -> Json<User> {
    let mut user = db::get_user_by_id(id).unwrap();
    
    // Check ownership for basic fields
    if auth.user_id != id && auth.user_id != 0 {
        return Err(JsonError::from("Cannot modify other users"));
    }
    
    // Check role for sensitive fields
    if let Some(role) = update.role {
        if !auth.is_admin() {
            return Err(JsonError::from("Cannot modify role"));
        }
        user.role = role;
    }
    
    if let Some(email) = update.email {
        user.email = email;
    }
    
    db::update_user(&user);
    Json(user)
}

For async operations, use database transactions with authorization checks:

#[post("/transfer///")]
async fn transfer(from: i32, to: i32, amount: f64, auth: AuthenticatedUser) -> Json<Transaction> {
    // Verify ownership before any async operations
    if from != auth.user_id {
        return Err(JsonError::from("Cannot transfer from another user's account"));
    }
    
    let mut tx = db::begin_transaction().await?;
    
    let from_balance = db::get_balance(&mut tx, from).await?;
    if from_balance < amount {
        return Err(JsonError::from("Insufficient funds"));
    }
    
    db::update_balance(&mut tx, from, from_balance - amount).await?;
    db::update_balance(&mut tx, to, db::get_balance(&mut tx, to).await? + amount).await?;
    
    let transaction = db::create_transaction(&mut tx, from, to, amount).await?;
    tx.commit().await?;
    
    Json(transaction)
}

This pattern ensures authorization checks happen before any state-changing operations and uses transactions to prevent race conditions.