Do not modify innerHTML or outerHTML

Documentos > Datadog Security > Seguridad del código > Static Code Analysis (SAST) > Reglas de SAST > Do not modify innerHTML or outerHTML

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Metadata

ID: javascript-browser-security/inner-outer-html

Language: JavaScript

Severity: Warning

Category: Security

CWE: 79

Description

Properties like innerHTML and outerHTML should not be modified directly unless such modifications are clearly reviewed. Modifying innerHTML or outerHTML using user inputs that has not been validated can lead to XSS injection.

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Non-Compliant Code Examples

function nonCompliant(argument) {
  const content = '<div>' + argument + '</div>';
  document.write(content);
}

function nonCompliant(myArgument) {
  document.body.outerHTML = myArgument;
}

if (typeof(SERVER_DOMAIN) === 'undefined') {
   window.location.replace("/unconfigured.html");
}

const RECEIVE_URL = SERVER_DOMAIN + "/challenge_scoreboard.html" + "?origin=" + get_domain();

var window_ref = null;

document.getElementById("username").focus();

function store_username() {
   var username;
   var username_obj;

   username_obj = document.getElementById("username");
   username = username_obj.value

   var welcome;
   welcome = document.getElementById("welcome");
   welcome.innerHTML = "Welcome " + html_encode (username);

   var set_username;
   set_username = document.getElementById("set_username");
   set_username.style.display="none";

   var game;
   game = document.getElementById("game");
   game.style.display="inline";

   start_game();
   // have to do time out so the window can open
   setTimeout (function () {send_username(username);}, 1000);

   return false;
}

Compliant Code Examples

import { xss, xssStrip, xssEscapeHtml } from '@/utils/xss';

function sanitizeHtml(el, something) {
    if (Array.isArray(something.value)) {
      el.innerHTML = xss(something.value);
    } else if (something.strip) {
      el.innerHTML = xssStrip(something.value);
    } else if (something.escape) {
      el.innerHTML = xssEscapeHtml(something.value);
    } else {
      el.innerHTML = xss(binding.value);
    }
  }
}

export default sanitizeHtml;