使用 windows.location.href 时的跨站点脚本

Question

我正在使用 Windows.location.href=URl 从 java 脚本导航到 MVC 控制器方法。 我想在重定向时避免任何 XSS 攻击。我该怎么办

Answer 1

您可以编写自己的 XSS 清理函数

function encodeHTML(s) {
    return s.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/"/g, '&quot;');
}

window.location.href = encodeHTML(URI);

Answer 2

这应该很容易。我已经为你准备好了解决方案。首先是一些理论上的理解

规则 #0 - 切勿插入不受信任的数据，除非在允许的位置

<script>...NEVER PUT UNTRUSTED DATA HERE...</script>   directly in a script

<style>...NEVER PUT UNTRUSTED DATA HERE...</style>   directly in CSS

规则 #1 - 在将不受信任的数据插入 HTML 元素内容之前，HTML 和 JavaScript 转义

HTML ...在将不受信任的数据放在这里之前转义... JS

<script>alert('...ESCAPE UNTRUSTED DATA BEFORE PUTTING HERE...')</script>     inside a quoted string

转义

& --> &
 < --> &lt;
 > --> &gt;
 " --> &quot;
 ' --> &#x27;     &apos; not recommended because its not in the HTML spec (See: section 24.4.1) &apos; is in the XML and XHTML specs.
 / --> &#x2F;     forward s

包含 lash 是因为它有助于结束 HTML 实体

确保返回的 Content-Type 标头是 application/json 而不是 text/html。

进入编码部分

以下内容会对您有所帮助

private String killXSS(String value) {
        if (value != null) {
            // NOTE: It's highly recommended to use the ESAPI library and uncomment the following line to
            // avoid encoded attacks.
            // value = ESAPI.encoder().canonicalize(value);

            // Avoid null characters
            value = value.replaceAll("", "");

            // Avoid anything between script tags
            Pattern scriptPattern = Pattern.compile("<script>(.*?)</script>", Pattern.CASE_INSENSITIVE);
            value = scriptPattern.matcher(value).replaceAll("");

            // Avoid anything in a src='...' type of expression
            scriptPattern = Pattern.compile("src[\r\n]*=[\r\n]*\\\'(.*?)\\\'", Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
            value = scriptPattern.matcher(value).replaceAll("");

            scriptPattern = Pattern.compile("src[\r\n]*=[\r\n]*\\\"(.*?)\\\"", Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
            value = scriptPattern.matcher(value).replaceAll("");

            // Remove any lonesome </script> tag
            scriptPattern = Pattern.compile("</script>", Pattern.CASE_INSENSITIVE);
            value = scriptPattern.matcher(value).replaceAll("");

            // Remove any lonesome <script ...> tag
            scriptPattern = Pattern.compile("<script(.*?)>", Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
            value = scriptPattern.matcher(value).replaceAll("");

            // Avoid eval(...) expressions
            scriptPattern = Pattern.compile("eval\\((.*?)\\)", Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
            value = scriptPattern.matcher(value).replaceAll("");

            // Avoid expression(...) expressions
            scriptPattern = Pattern.compile("expression\\((.*?)\\)", Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
            value = scriptPattern.matcher(value).replaceAll("");

            // Avoid javascript:... expressions
            scriptPattern = Pattern.compile("javascript:", Pattern.CASE_INSENSITIVE);
            value = scriptPattern.matcher(value).replaceAll("");

            // Avoid vbscript:... expressions
            scriptPattern = Pattern.compile("vbscript:", Pattern.CASE_INSENSITIVE);
            value = scriptPattern.matcher(value).replaceAll("");

            // Avoid onload= expressions
            scriptPattern = Pattern.compile("onload(.*?)=", Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
            value = scriptPattern.matcher(value).replaceAll("");
        }
        return value;
    }

确保您发送到服务器的每个请求都通过上述代码剥离，您将永远不会成为 XSS 的受害者。