How to test XSS vulnerability using Selenium WebDriver?

Question

I am in the process of writing automated tests for my application. One of the tests I have thought of is to check for XSS vulnerabilities (specifically script/markup injection) in the application.

Suppose I have a field that accepts a text input:

<input id="messageInput" name="message" />

And assume it prints the input message else where as follows:

<p id="messageOutput">You entered ${message}</p>

The simplest of test cases would attempt to feed in markup such as <b>Hello</b> instead of plain text.

How can I verify that the markup isn't actually rendered on the browser? One dirty way I can think of is to go down to the element which displays the input.

@FindBy(id = "messageOutput")
WebElement messageOutput;

public boolean isMarkupRendered() {
    try {
        messageOutput.findElement(By.tagName("b"));
        return true;
    } catch (NoSuchElementException e) {
        return false;
    }
}

However, this ties my method to the kind of test data that I may supply - it isn't generic enough to work with inputs such as

<script>document.body.style.backgroundColor='red'</script>

Any suggestions here? Does Selenium offer a cleaner way of doing this?

Answer 1

Not so far I've come across with getting element css properties (in particular, color):

 public String jsGetColor(String css){

        JavascriptExecutor js = (JavascriptExecutor) driver;
        StringBuilder stringBuilder = new StringBuilder();
        stringBuilder.append("var x=$(\'"+css+"\');");
        stringBuilder.append("return x.css('color')");
        String res= (String) js.executeScript(stringBuilder.toString());
        return res;

    }

So the idea is to manipulate with css properties of the element if you definitely know what kind of element it be: text , picture , etc.

-How can I verify that the markup isn't actually rendered on the browser? - there are a lot of ways for veryfying that somehing is present or absent with selenium:

input.findElements(By.xpath("//xpath")).size() > 0


driver.findElement(By.cssSelector(html>blablabla....)).isDisplayed()

public bool IsElementPresent(By selector)
{
    return driver.FindElements(selector).Any();
}

Hope this somehow helps you)