Formula Injection in Buffalo with Cockroachdb

Formula Injection occurs when user-controlled data is interpreted as part of a query language or formula, leading to unintended behavior or data exposure. In the Buffalo web framework, when integrating with Cockroachdb, this risk arises if dynamic values—such as identifiers, sort orders, or filter expressions—are directly interpolated into SQL strings or ORM queries without proper sanitization or parameterization.

Buffalo encourages developers to use pop for data access, which relies on prepared statements when using its query building methods. However, if a developer constructs queries using string concatenation—especially for clauses like ORDER BY, SELECT column lists, or table names—user input can alter the logical structure of the query. For example, an order parameter from a request like /users?sort=name might be appended directly into a raw SQL fragment, enabling an attacker to inject additional expressions or terminate statements prematurely.

Cockroachdb, while PostgreSQL-wire compatible, introduces nuances around distributed SQL and implicit type casting that can amplify injection impact. If untrusted input is used to influence Cockroachdb-specific constructs—such as AS OF SYSTEM TIME clauses, SHOW commands, or database/table names—the injected content may be interpreted as valid Cockroachdb syntax, bypassing intended constraints. An attacker could manipulate a LIMIT or OFFSET value to cause excessive resource consumption or data leakage, or exploit comment sequences (--) to truncate intended filtering logic.

The combination of Buffalo’s flexible request handling and Cockroachdb’s extended SQL dialect increases the attack surface when developers assume ORM-level safety without validating or restricting dynamic schema elements. Since pop does not automatically parameterize identifiers or clause components, any user-influenced schema or expression must be explicitly validated against a strict allowlist. MiddleBrick scans can detect such patterns in unauthenticated API surfaces, flagging inputs that traverse query-building logic without sufficient sanitization, thereby highlighting Formula Injection risks tied to this specific tech stack.

To mitigate Formula Injection in Buffalo with Cockroachdb, always prefer parameterized queries and avoid interpolating user input into SQL text. For dynamic identifiers or clauses, use strict allowlists and explicit mapping rather than raw concatenation.

1. Safe ORDER BY with allowlist validation

Validate user-supplied sort fields against a predefined set of columns. Do not directly embed the value in SQL.

// GOOD: Allowlist-based ordering in Buffalo controller
validColumns := map[string]string{
  "name":  "name",
  "email": "email",
  "id":    "id",
}
sortBy := params.Get("sort", "id")
orderCol, ok := validColumns[sortBy]
if !ok {
  orderCol = "id"
}
users := []model.User{}
if err := db.All(&users, pop.Select("*").OrderBy(orderCol + " ASC")); err != nil {
  // handle error
}

2. Parameterized WHERE clauses with placeholders

Use pop.Where with named or positional placeholders to ensure values are never interpreted as executable syntax.

// GOOD: Parameterized filtering in Buffalo model or controller
users := []model.User{}
err := db.All(&users, 
  pop.Where("status = $1", "active"),
  pop.Where("created_at >= $1", time.Now().AddDate(0, -1, 0)),
)

3. Avoid dynamic Cockroachdb clauses in raw SQL

If you must use raw SQL, never concatenate user input into clauses such as AS OF SYSTEM TIME or SHOW. Instead, use fixed values or configuration-driven defaults.

// GOOD: Fixed or config-driven AS OF SYSTEM TIME usage
timestamp := "2024-01-01 00:00:00+00" // from config, not user input
var result interface{}
err := db.Raw(`SELECT * FROM users AS OF SYSTEM TIME $1`, timestamp).All(&result)

4. Restrict identifier quoting and schema traversal

When dynamically selecting columns or tables, map user input to safe identifiers using a lookup table, and avoid building identifiers via string interpolation.

// GOOD: Mapping user input to safe identifiers
tableMap := map[string]string{
  "profile": "users_profiles",
  "settings": "user_settings",
}
tableName, exists := tableMap[params.Get("table", "users")]
if !exists {
  tableName = "users"
}
rows, err := db.Query(fmt.Sprintf("SELECT * FROM %s WHERE id = $1", tableName), id)

5. Use Buffalo helpers for query building

Leverage pop methods that generate parameterized SQL. Avoid Raw unless necessary, and validate any fragments used.

// GOOD: Using pop.Select with controlled columns
query := pop.Select("id", "name", "email").Where("org_id = $1", orgID)
users := []model.User{}
if err := db.All(&users, query); err != nil {
  // handle error
}