Command Injection in Echo Go with Cockroachdb

Command Injection occurs when an attacker can influence shell commands executed by an application. In an Echo Go service that interacts with Cockroachdb, the risk arises when user-controlled input is concatenated into commands that are executed on the host, rather than being passed safely as parameters. Cockroachdb provides a Go driver that uses parameterized queries for SQL execution, which prevents SQL injection, but it does not protect you if you build shell commands for operations like backups, restores, or invoking external scripts that include user input.

Consider an endpoint that accepts a database name from a request and runs a cockroach dump via exec.Command. If the endpoint does not validate or sanitize the input, an attacker can inject additional shell commands using shell metacharacters such as ;, &&, or backticks. For example, a request with db_name=mydb;cat /etc/passwd could lead to unauthorized file reads. Even though Cockroachdb itself is not compromised directly via SQL injection in this scenario, the command injection exposes the underlying host, potentially leading to data exfiltration or further compromise.

Echo Go middleware that logs request details might also inadvertently include unsanitized input in log entries that are later processed by scripts, creating an indirect command injection path. If those logs are fed into a monitoring tool that executes shell commands based on user-supplied fields, the attack surface expands. The combination of a web framework like Echo that simplifies routing and middleware, a database driver for Cockroachdb that encourages safe SQL practices, and the misuse of OS commands creates a scenario where developers may assume safety due to parameterized queries while overlooking shell command construction.

Real-world attack patterns include attempts to exploit weak input validation in administrative endpoints, such as importing data or running migrations. An attacker might try to inject $(id) or backticks to execute arbitrary shell commands. This is distinct from SQL injection, which targets the database via malformed queries; here, the vulnerability is in the interaction between the Go runtime, the operating system shell, and the Cockroachdb tooling, even when the database driver itself is secure.

To detect such issues, scanning tools like middleBrick analyze unauthenticated attack surfaces and include checks for Unsafe Consumption and Input Validation. They examine how user input flows through the application and whether it reaches OS-level commands without proper sanitization or use of safe APIs like exec.CommandContext with explicit argument lists.

Remediation focuses on avoiding shell command construction with user input and using Cockroachdb Go driver patterns that keep data and commands separate. Always prefer the driver's SQL execution methods with placeholders instead of string interpolation.

// Unsafe pattern to avoid: building a shell command with user input
package main

import (
    "github.com/labstack/echo/v4"
    "os/exec"
    "net/http"
)

func unsafeHandler(c echo.Context) error {
    dbName := c.QueryParam("db")
    cmd := exec.Command("cockroach", "dump", dbName) // vulnerable if dbName contains shell metacharacters
    // ... execute and return output
    return c.String(http.StatusOK, "done")
}

The above example is unsafe because dbName is directly concatenated into the command arguments, allowing shell injection if the underlying shell is invoked (which can happen depending on how exec.Command processes arguments in the Go runtime environment). An attacker could supply db_name=mydb;cat /etc/passwd and affect the host.

Secure approach using explicit arguments and avoiding the shell:

// Safe pattern: use explicit arguments without shell interpretation
package main

import (
    "github.com/labstack/echo/v4"
    "os/exec"
    "net/http"
)

func safeHandler(c echo.Context) error {
    dbName := c.QueryParam("db")
    // Arguments are passed directly to the binary, no shell involved
    cmd := exec.Command("cockroach", "dump", "--database="+dbName)
    // Consider additional validation: ensure dbName matches expected pattern
    if !isValidDBName(dbName) {
        return c.String(http.StatusBadRequest, "invalid database name")
    }
    // ... execute command safely
    return c.String(http.StatusOK, "done")
}

func isValidDBName(name string) bool {
    // Allow only alphanumeric and underscore
    for _, r := range name {
        if !(r >= 'a' && r <= 'z' || r >= 'A' && r <= 'Z' || r >= '0' && r <= '9' || r == '_') {
            return false
        }
    }
    return name != "" && len(name) <= 63
}

For Cockroachdb operations, use the Go SQL driver with parameterized queries to prevent SQL injection, which is a separate but related concern:

// Safe database interaction with Cockroachdb using sqlx or standard database/sql
package main

import (
    "github.com/labstack/echo/v4"
    "database/sql"
    _ "github.com/lib/pq"
    "net/http"
)

func queryHandler(c echo.Context) error {
    db, err := sql.Open("postgres", "postgresql://user@localhost:26257/defaultdb?sslmode=disable")
    if err != nil {
        return c.String(http.StatusInternalServerError, "failed to connect")
    }
    defer db.Close()

    tableName := c.QueryParam("table")
    // Use parameterized query if supported; for Cockroachdb, placeholders are $1, $2, etc.
    var count int
    err = db.QueryRow("SELECT count(*) FROM " + tableName + " WHERE status = $1", "active").Scan(&count)
    if err != nil {
        return c.String(http.StatusInternalServerError, "query failed")
    }
    return c.JSON(http.StatusOK, map[string]int{"count": count})
}

Note: The above SQL example still concatenates tableName, which is not safe. In practice, use whitelisting or schema-qualified identifiers. The key remediation is to avoid constructing shell commands with user input and to rely on the Cockroachdb Go driver's safe parameter handling for SQL. middleBrick can help identify command injection risks in your scan reports, and the Pro plan provides continuous monitoring to catch regressions in CI/CD pipelines.