Auth Bypass in Echo Go with Cockroachdb

An authentication bypass in an Echo Go service that uses Cockroachdb typically arises when session or token validation is handled at the application layer without enforcing strict, per-request verification against the database. Because Cockroachdb is often used to store user credentials, roles, and session state, any inconsistency between cached identity and source-of-truth data can lead to insecure authorization decisions.

For example, an endpoint may rely on a cached JWT payload that includes a user ID and role, but never re-query Cockroachdb to confirm that the user is still active, has not been revoked, and is permitted for the targeted resource. If the JWT is accepted without checking revocation lists or tenant-specific permissions stored in Cockroachdb, an attacker can reuse a token after deprovisioning or escalate privileges by manipulating claims that are not validated against the database.

Another common pattern is binding user-supplied identifiers (e.g., userID) directly to database rows without verifying that the authenticated subject has access to that identifier. In Echo Go, middleware may set a context key with the user ID from the token, and subsequent handlers may construct SQL like SELECT * FROM profiles WHERE user_id = $1 using that ID. If the handler does not confirm that the authenticated user matches the requested ID in Cockroachdb, an attacker can change the path parameter to access other users' data, resulting in a BOLA/IDOR that effectively bypasses authentication controls at the route level.

With Cockroachdb, multi-region deployments and serializable isolation can also expose subtle timing or transaction anomalies that, when combined with improper error handling in Echo Go, may leak whether a user exists or whether a row was updated. An attacker can use these side channels to infer valid user identifiers and craft authenticated requests without a valid session, especially when error responses differ between missing rows and invalid credentials.

Proper integration requires treating the database as the definitive source for access decisions on every request. This means validating tokens, checking revocation, confirming tenant scope, and re-verifying user-to-resource mapping against Cockroachdb immediately before performing sensitive operations, rather than relying on cached context established earlier in the middleware chain.

To secure Echo Go applications using Cockroachdb, enforce per-request authorization against the database and avoid trusting client-supplied identifiers or cached claims without verification. The following patterns demonstrate secure handling of authentication and authorization.

1. Validate session and user status on each request
Use middleware to decode the JWT, then re-check the user’s active status and roles in Cockroachdb before allowing access.

// middleware/auth.go
package middleware

import (
	"context"
	"net/http"

	"github.com/labstack/echo/v4"
	"github.com/lib/pq"
)

type UserContextKey string

const CurrentUser UserContextKey = "current_user"

func AuthMiddleware(db *sql.DB) echo.MiddlewareFunc {
	return func(next echo.HandlerFunc) echo.HandlerFunc {
		return func(c echo.Context) error {
			authHeader := c.Request().Header.Get("Authorization")
			if authHeader == "" {
				return echo.NewHTTPError(http.StatusUnauthorized, "missing authorization header")
			}
			// Assume Bearer <token> extraction
			tokenString := authHeader[len("Bearer "):]
			claims, err := validateToken(tokenString)
			if err != nil {
				return echo.NewHTTPError(http.StatusUnauthorized, "invalid token")
			}

			var active bool
			err = db.QueryRowContext(c.Request().Context(),
				"SELECT active FROM users WHERE id = $1", claims.UserID,
			).Scan(&active)
			if err != nil {
				return echo.NewHTTPError(http.StatusUnauthorized, "user not found")
			}
			if !active {
				return echo.NewHTTPError(http.StatusForbidden, "account disabled")
			}

			c.Set(string(CurrentUser), claims.UserID)
			return next(c)
		}
	}
}

2. Enforce row-level ownership for Cockroachdb queries
When querying user-specific data, always include the authenticated user ID in the WHERE clause and verify that a row was returned.

// handlers/profile.go
package handlers

import (
	"database/sql"
	"net/http"

	"github.com/labstack/echo/v4"
)

func GetProfile(c echo.Context) error {
	userID := c.Get(middleware.CurrentUser).(string)
	requestedID := c.Param("user_id")
	if userID != requestedID {
		return echo.NewHTTPError(http.StatusForbidden, "access denied")
	}

	var profile Profile
	err := c.Get("db").(*sql.DB).QueryRowContext(c.Request().Context(),
		"SELECT id, display_name, email FROM profiles WHERE user_id = $1", userID,
	).Scan(&profile.ID, &profile.DisplayName, &profile.Email)
	if err != nil {
		if err == sql.ErrNoRows {
			return echo.NewHTTPError(http.StatusNotFound, "profile not found")
		}
		return echo.NewHTTPError(http.StatusInternalServerError, "unable to load profile")
	}
	return c.JSON(http.StatusOK, profile)
}

3. Use Cockroachdb-specific isolation and error handling
Prefer parameterized queries and handle pq-specific error codes to avoid information leakage. Do not rely on error messages to differentiate between missing rows and invalid input.

// db/tx.go
package db

import (
	"context"
	"database/sql"

	"github.com/lib/pq"
)

func EnsureUserInTenant(ctx context.Context, db *sql.DB, userID, tenantID string) error {
	const query = `
		SELECT 1 FROM tenant_memberships 
		WHERE user_id = $1 AND tenant_id = $2 FOR UPDATE`
	row := db.QueryRowContext(ctx, query, userID, tenantID)
	var found int
	if err := row.Scan(&found); err != nil {
		if err == sql.ErrNoRows {
			return sql.ErrNoRows
		}
		// Log structured error without exposing internals
		return pq.Error{Code: "XX000", Message: "tenant access check failed"}
	}
	return nil
}

4. Apply least privilege in Cockroachdb connections
Configure the database user used by Echo Go with minimal required permissions (e.g., read/write only on necessary tables) and avoid using superuser roles in production handlers.