Ldap Injection in Echo Go with Cockroachdb

LDAP injection occurs when an attacker can manipulate LDAP query construction through uncontrolled input. In an Echo Go service that delegates authentication or group membership checks to Cockroachdb-stored LDAP-like data (for example, a table that models directory entries), injection becomes possible if input is concatenated into query strings rather than parameterized. Cockroachdb, while PostgreSQL-wire compatible, does not inherently protect you from injection in the application layer; if Go code builds LDAP filter strings using user input and then executes them via sql.Exec or sql.Query, malicious payloads can alter filter logic.

Consider an Echo handler that binds a username and password, then constructs an LDAP-style filter to validate credentials against a Cockroachdb table storing directory entries:

username := c.FormValue("username")
filter := fmt.Sprintf("(uid=%s)", username)
rows, err := db.QueryContext(ctx, "SELECT dn, password_hash FROM ldap_entries WHERE "+filter)

If username is supplied as admin)(uid=*)(, the resulting filter becomes (uid=admin)(uid=*)(, which can bypass authentication or cause unintended data exposure. Because Cockroachdb executes the SQL string as written, the injected syntax changes the predicate logic. An attacker may enumerate users, extract hashes, or force OR conditions by closing parentheses and adding new clauses. The risk is amplified when the application also uses the same Cockroachdb instance for audit logs or configuration, as injection may pivot to modify or delete sensitive records.

Echo Go does not sanitize inputs by default; it merely provides request routing and parameter extraction. Therefore, the framework does not mitigate injection. The combination of Echo Go’s flexibility in handling request parameters and Cockroachdb’s execution of dynamic SQL places the burden entirely on the developer to enforce strict input validation and parameterized queries. Without these controls, the attack surface includes authentication bypass, information disclosure, and potential lateral movement if the directory data is linked to other services.

Additionally, if the service exposes an unauthenticated endpoint that triggers LDAP search construction based on query parameters, middleBrick’s unauthenticated scan may flag this as an SSRF or injection risk during its parallel checks, including input validation and authentication assessments. The scanner does not fix the issue but highlights where user-controlled data reaches SQL construction.

Remediation centers on avoiding string concatenation for SQL and LDAP filter construction, and strictly validating input formats. Use prepared statements with parameterized queries so Cockroachdb treats user data strictly as values, never as executable syntax. For LDAP filter components that must be embedded in SQL, encode or escape special LDAP characters and validate against a strict allow-list (e.g., alphanumeric usernames with optional hyphen/underscore).

Below is a secure pattern for querying Cockroachdb in Echo Go using parameterized SQL:

import (
    "context"
    "database/sql"
    "net/http"
    "github.com/labstack/echo/v4"
)

type Creds struct {
    Username string `json:"username" form:"username"`
    Password string `format:"password" form:"password"`
}

func authenticate(c echo.Context) error {
    ctx := c.Request().Context()
    creds := new(Creds)
    if err := c.Bind(creds); err != nil {
        return echo.NewHTTPError(http.StatusBadRequest, "invalid payload")
    }
    if err := c.Validate(creds); err != nil {
        return echo.NewHTTPError(http.StatusBadRequest, "invalid input")
    }

    var dn, passwordHash string
    // Parameterized query prevents injection into SQL
    err := db.QueryRowContext(ctx,
        "SELECT dn, password_hash FROM ldap_entries WHERE uid=$1",
        creds.Username).Scan(&dn, &passwordHash)
    if err == sql.ErrNoRows {
        return echo.NewHTTPError(http.StatusUnauthorized, "invalid credentials")
    }
    if err != nil {
        return echo.NewHTTPError(http.StatusInternalServerError, "database error")
    }

    // Verify passwordHash using your chosen secure comparison
    if !verifyPassword(creds.Password, passwordHash) {
        return echo.NewHTTPError(http.StatusUnauthorized, "invalid credentials")
    }
    return c.JSON(http.StatusOK, map[string]string{"dn": dn})
}

If you must construct an LDAP filter for directory operations, build it with proper escaping rather than string concatenation:

import (
    "github.com/Masterminds/semver/v3"
    "strings"
)

// escapeLDAPSpecialChars ensures characters like *, (, ), \, \x00 are handled
func escapeLDAPSpecialChars(input string) string {
    // Replace * with \2a, ( with \28, ) with \29, \ with \5c, \x00 with \00
    // This is a simplified example; use a well-vetted library for production
    input = strings.ReplaceAll(input, "\\", "\\5c")
    input = strings.ReplaceAll(input, "*", "\\2a")
    input = strings.ReplaceAll(input, "(", "\\28")
    input = strings.ReplaceAll(input, ")", "\\29")
    input = strings.ReplaceAll(input, "\x00", "\\00")
    return input
}

func buildSearchFilter(username string) string {
    safeUser := escapeLDAPSpecialChars(username)
    return "(uid=" + safeUser + ")"
}

In the dashboard, you can track how often scans flag LDAP injection patterns; in the CLI, running middlebrick scan <url> will surface findings under input validation and authentication. For teams using GitHub Action, adding the check ensures that any regression in query construction fails the build before deployment. The MCP server can surface these risks directly in IDE tooling when developers author queries, reinforcing secure patterns without disrupting workflow.